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Read the following passage and write the letter A, B, C or D on the top of the first page to indicate the correct answer to each of the questions.

In the course of its history, human inventions have dramatically increased the average amount of energy available for use per person. Primitive peoples in cold regions burned wood and animal dung to heat their caves, cook food, and drive off animals by fire. The first step toward the developing of more efficient fuels was taken when people discovered that they could use vegetable oils and animal fats in lieu of gathered or cut wood. Charcoal gave off more intensive heat than wood and was more easily obtainable than organic fats. The Greeks first began to use coal for metal smelting in the 4th century, but it did not come into extensive use until the Industrial Revolution.

In the 1700s, at the beginning of the Industrial Revolution, most energy used in the United States and other nations undergoing industrialization was obtained from perpetual and renewable sources, such as wood, water streams, domesticated animal labor, and wind. These were predominantly locally available supplies. By mid-1800s, 91 percent of all commercial energy consumed in the United States and European countries was obtained from wood. However, at he beginning of the 20th century, coal became a major energy source and replaced wood in industrializing countries. Although in most regions and climate zones wood was more readily accessible than coal, the latter represents a more concentrated source of energy. In 1910, natural gas and oil firmly replaced coal as the main source of fuel because they are lighter and, therefore, cheaper to transport. They burned more cleanly than coal and polluted less. Unlike coal, oil could be refined to manufacture liquid fuels for vehicles, a very important consideration in the early 1900s, when the automobile arrived on the scene.

By 1984, non-renewable fossil fuels, such as oil, coal, and natural gas, provided over 82 percent of the commercial and industrial energy used in the world. Small amounts of energy were derived from nuclear fission, and the remaining 16 percent came from burning direct perpetual and renewable fuels, such as biomass. Between 1700 and 1986, a large number of countries shifted from the use of energy from local sources to a centralized generation of hydropower and solar energy converted to electricity. The energy derived from non-renewable fossil fuels has been increasingly produced in one location and transported to another, as is the case with most automobile fuels. In countries with private, rather than public transportation, the age of non-renewable fuels has created a dependency on a finite resource that will have to be replaced.

Alternative fuel sources are numerous, and shale oil and hydrocarbons are just two examples. The extraction of shale oil from large deposits in Asian and European regions has proven to be labor consuming and costly. The resulting product is sulfur-and nitrogen-rich, and large scale extractions are presently prohibitive. Similarly, the extraction of hydrocarbons from tar sands in Alberta and Utah is complex. Semi-solid hydrocarbons cannot be easily separated from the sandstone and limestone that carry them, and modern technology is not sufficiently versatile for a large-scale removal of the material. However, both sources of fuel may eventually be needed as petroleum prices continue to rise and limitations in fossil fuel availability make alternative deposits more attractive.
Question:
The author of the passage implies that in the 1700s, sources of energy were

Read the following passage and write the letter A, B, C or D on the top of the first page to indicate the correct answer to each of the questions.

In the course of its history, human inventions have dramatically increased the average amount of energy available for use per person. Primitive peoples in cold regions burned wood and animal dung to heat their caves, cook food, and drive off animals by fire. The first step toward the developing of more efficient fuels was taken when people discovered that they could use vegetable oils and animal fats in lieu of gathered or cut wood. Charcoal gave off more intensive heat than wood and was more easily obtainable than organic fats. The Greeks first began to use coal for metal smelting in the 4th century, but it did not come into extensive use until the Industrial Revolution.

In the 1700s, at the beginning of the Industrial Revolution, most energy used in the United States and other nations undergoing industrialization was obtained from perpetual and renewable sources, such as wood, water streams, domesticated animal labor, and wind. These were predominantly locally available supplies. By mid-1800s, 91 percent of all commercial energy consumed in the United States and European countries was obtained from wood. However, at he beginning of the 20th century, coal became a major energy source and replaced wood in industrializing countries. Although in most regions and climate zones wood was more readily accessible than coal, the latter represents a more concentrated source of energy. In 1910, natural gas and oil firmly replaced coal as the main source of fuel because they are lighter and, therefore, cheaper to transport. They burned more cleanly than coal and polluted less. Unlike coal, oil could be refined to manufacture liquid fuels for vehicles, a very important consideration in the early 1900s, when the automobile arrived on the scene.

By 1984, non-renewable fossil fuels, such as oil, coal, and natural gas, provided over 82 percent of the commercial and industrial energy used in the world. Small amounts of energy were derived from nuclear fission, and the remaining 16 percent came from burning direct perpetual and renewable fuels, such as biomass. Between 1700 and 1986, a large number of countries shifted from the use of energy from local sources to a centralized generation of hydropower and solar energy converted to electricity. The energy derived from non-renewable fossil fuels has been increasingly produced in one location and transported to another, as is the case with most automobile fuels. In countries with private, rather than public transportation, the age of non-renewable fuels has created a dependency on a finite resource that will have to be replaced.

Alternative fuel sources are numerous, and shale oil and hydrocarbons are just two examples. The extraction of shale oil from large deposits in Asian and European regions has proven to be labor consuming and costly. The resulting product is sulfur-and nitrogen-rich, and large scale extractions are presently prohibitive. Similarly, the extraction of hydrocarbons from tar sands in Alberta and Utah is complex. Semi-solid hydrocarbons cannot be easily separated from the sandstone and limestone that carry them, and modern technology is not sufficiently versatile for a large-scale removal of the material. However, both sources of fuel may eventually be needed as petroleum prices continue to rise and limitations in fossil fuel availability make alternative deposits more attractive.
Question:
It can be inferred from the first paragraph that

Read the following passage and write the letter A, B, C or D on the top of the first page to indicate the correct answer to each of the questions.

In the course of its history, human inventions have dramatically increased the average amount of energy available for use per person. Primitive peoples in cold regions burned wood and animal dung to heat their caves, cook food, and drive off animals by fire. The first step toward the developing of more efficient fuels was taken when people discovered that they could use vegetable oils and animal fats in lieu of gathered or cut wood. Charcoal gave off more intensive heat than wood and was more easily obtainable than organic fats. The Greeks first began to use coal for metal smelting in the 4th century, but it did not come into extensive use until the Industrial Revolution.

In the 1700s, at the beginning of the Industrial Revolution, most energy used in the United States and other nations undergoing industrialization was obtained from perpetual and renewable sources, such as wood, water streams, domesticated animal labor, and wind. These were predominantly locally available supplies. By mid-1800s, 91 percent of all commercial energy consumed in the United States and European countries was obtained from wood. However, at he beginning of the 20th century, coal became a major energy source and replaced wood in industrializing countries. Although in most regions and climate zones wood was more readily accessible than coal, the latter represents a more concentrated source of energy. In 1910, natural gas and oil firmly replaced coal as the main source of fuel because they are lighter and, therefore, cheaper to transport. They burned more cleanly than coal and polluted less. Unlike coal, oil could be refined to manufacture liquid fuels for vehicles, a very important consideration in the early 1900s, when the automobile arrived on the scene.

By 1984, non-renewable fossil fuels, such as oil, coal, and natural gas, provided over 82 percent of the commercial and industrial energy used in the world. Small amounts of energy were derived from nuclear fission, and the remaining 16 percent came from burning direct perpetual and renewable fuels, such as biomass. Between 1700 and 1986, a large number of countries shifted from the use of energy from local sources to a centralized generation of hydropower and solar energy converted to electricity. The energy derived from non-renewable fossil fuels has been increasingly produced in one location and transported to another, as is the case with most automobile fuels. In countries with private, rather than public transportation, the age of non-renewable fuels has created a dependency on a finite resource that will have to be replaced.

Alternative fuel sources are numerous, and shale oil and hydrocarbons are just two examples. The extraction of shale oil from large deposits in Asian and European regions has proven to be labor consuming and costly. The resulting product is sulfur-and nitrogen-rich, and large scale extractions are presently prohibitive. Similarly, the extraction of hydrocarbons from tar sands in Alberta and Utah is complex. Semi-solid hydrocarbons cannot be easily separated from the sandstone and limestone that carry them, and modern technology is not sufficiently versatile for a large-scale removal of the material. However, both sources of fuel may eventually be needed as petroleum prices continue to rise and limitations in fossil fuel availability make alternative deposits more attractive.
Question:
What is the main topic of the passage?

Read the following passage and write the letter A, B, C or D on the top of the first page to indicate the correct answer to each of the questions.

In 1972. a century after the first national park in the United States was established at Yellowstone, legislation was passed to create the National Marine Sanctuaries Program. The intent of this legislation was to provide protection to selected coastal habitats similar to that existing for land areas designated as national parks. The designation of an areas a marine sanctuary indicates that it is a protected area, just as a national park is. People are permitted to visit and observe there, but living organisms and their environments may not be harmed or removed.

The National Marine Sanctuaries Program is administered by the National Oceanic and Atmospheric Administration, a branch of the United States Department of Commerce. Initially, 70 sites were proposed as candidates for sanctuary status. Two and a half decades later, only fifteen sanctuaries had been designated, with half of these established after 1978. They range in size from the very small (less than 1 square kilometer) Fagatele Bay National Marine Sanctuary in American Samoa to the Monterey Bay National Marine Sanctuary in California, extending over 15,744 square kilometers.

The National Marine Sanctuaries Program is a crucial part of new management practices in which whole communities of species, and not just individual species, are offered some degree of protection from habitat degradation and overexploitation. Only in this way can a reasonable degree of marine species diversity be maintained in a setting that also maintains the natural interrelationships that exist among these species.

Several other types of marine protected areas exist in the United States and other countries. The National Estuarine Research Reserve System managed by the United States government, includes 23 designated and protected estuaries. Outside the United States, marine protected-area programs exist as marine parks, reserves and preserves.

Over 100 designated areas exist around the periphery of the Caribbean Sea. Others range from the well-known Australian Great Barrer Reef Marine Park to lesser-known parks in countries such as Thailand and Indonesia, where tourism is placing growing pressures on fragile coral reef systems. As state, national, and international agencies come to recognize the importance of conserving marine biodiversity, marine projected areas whether as sanctuaries,parks, or estuarine reserves, will play an increasingly important role in preserving that diversity.
Question:
The passage mentions which of the following as a threat to marine areas outside the United States?

Read the following passage and write the letter A, B, C or D on the top of the first page to indicate the correct answer to each of the questions.

In 1972. a century after the first national park in the United States was established at Yellowstone, legislation was passed to create the National Marine Sanctuaries Program. The intent of this legislation was to provide protection to selected coastal habitats similar to that existing for land areas designated as national parks. The designation of an areas a marine sanctuary indicates that it is a protected area, just as a national park is. People are permitted to visit and observe there, but living organisms and their environments may not be harmed or removed.

The National Marine Sanctuaries Program is administered by the National Oceanic and Atmospheric Administration, a branch of the United States Department of Commerce. Initially, 70 sites were proposed as candidates for sanctuary status. Two and a half decades later, only fifteen sanctuaries had been designated, with half of these established after 1978. They range in size from the very small (less than 1 square kilometer) Fagatele Bay National Marine Sanctuary in American Samoa to the Monterey Bay National Marine Sanctuary in California, extending over 15,744 square kilometers.

The National Marine Sanctuaries Program is a crucial part of new management practices in which whole communities of species, and not just individual species, are offered some degree of protection from habitat degradation and overexploitation. Only in this way can a reasonable degree of marine species diversity be maintained in a setting that also maintains the natural interrelationships that exist among these species.

Several other types of marine protected areas exist in the United States and other countries. The National Estuarine Research Reserve System managed by the United States government, includes 23 designated and protected estuaries. Outside the United States, marine protected-area programs exist as marine parks, reserves and preserves.

Over 100 designated areas exist around the periphery of the Caribbean Sea. Others range from the well-known Australian Great Barrer Reef Marine Park to lesser-known parks in countries such as Thailand and Indonesia, where tourism is placing growing pressures on fragile coral reef systems. As state, national, and international agencies come to recognize the importance of conserving marine biodiversity, marine projected areas whether as sanctuaries,parks, or estuarine reserves, will play an increasingly important role in preserving that diversity.
Question:
The word “periphery” in the passage is closest in meaning to

Read the following passage and write the letter A, B, C or D on the top of the first page to indicate the correct answer to each of the questions.

In 1972. a century after the first national park in the United States was established at Yellowstone, legislation was passed to create the National Marine Sanctuaries Program. The intent of this legislation was to provide protection to selected coastal habitats similar to that existing for land areas designated as national parks. The designation of an areas a marine sanctuary indicates that it is a protected area, just as a national park is. People are permitted to visit and observe there, but living organisms and their environments may not be harmed or removed.

The National Marine Sanctuaries Program is administered by the National Oceanic and Atmospheric Administration, a branch of the United States Department of Commerce. Initially, 70 sites were proposed as candidates for sanctuary status. Two and a half decades later, only fifteen sanctuaries had been designated, with half of these established after 1978. They range in size from the very small (less than 1 square kilometer) Fagatele Bay National Marine Sanctuary in American Samoa to the Monterey Bay National Marine Sanctuary in California, extending over 15,744 square kilometers.

The National Marine Sanctuaries Program is a crucial part of new management practices in which whole communities of species, and not just individual species, are offered some degree of protection from habitat degradation and overexploitation. Only in this way can a reasonable degree of marine species diversity be maintained in a setting that also maintains the natural interrelationships that exist among these species.

Several other types of marine protected areas exist in the United States and other countries. The National Estuarine Research Reserve System managed by the United States government, includes 23 designated and protected estuaries. Outside the United States, marine protected-area programs exist as marine parks, reserves and preserves.

Over 100 designated areas exist around the periphery of the Caribbean Sea. Others range from the well-known Australian Great Barrer Reef Marine Park to lesser-known parks in countries such as Thailand and Indonesia, where tourism is placing growing pressures on fragile coral reef systems. As state, national, and international agencies come to recognize the importance of conserving marine biodiversity, marine projected areas whether as sanctuaries,parks, or estuarine reserves, will play an increasingly important role in preserving that diversity.
Question:
According to the passage, all of the following are achievements of the National Marine Sanctuaries Program EXCEPT …..

Read the following passage and write the letter A, B, C or D on the top of the first page to indicate the correct answer to each of the questions.

In 1972. a century after the first national park in the United States was established at Yellowstone, legislation was passed to create the National Marine Sanctuaries Program. The intent of this legislation was to provide protection to selected coastal habitats similar to that existing for land areas designated as national parks. The designation of an areas a marine sanctuary indicates that it is a protected area, just as a national park is. People are permitted to visit and observe there, but living organisms and their environments may not be harmed or removed.

The National Marine Sanctuaries Program is administered by the National Oceanic and Atmospheric Administration, a branch of the United States Department of Commerce. Initially, 70 sites were proposed as candidates for sanctuary status. Two and a half decades later, only fifteen sanctuaries had been designated, with half of these established after 1978. They range in size from the very small (less than 1 square kilometer) Fagatele Bay National Marine Sanctuary in American Samoa to the Monterey Bay National Marine Sanctuary in California, extending over 15,744 square kilometers.

The National Marine Sanctuaries Program is a crucial part of new management practices in which whole communities of species, and not just individual species, are offered some degree of protection from habitat degradation and overexploitation. Only in this way can a reasonable degree of marine species diversity be maintained in a setting that also maintains the natural interrelationships that exist among these species.

Several other types of marine protected areas exist in the United States and other countries. The National Estuarine Research Reserve System managed by the United States government, includes 23 designated and protected estuaries. Outside the United States, marine protected-area programs exist as marine parks, reserves and preserves.

Over 100 designated areas exist around the periphery of the Caribbean Sea. Others range from the well-known Australian Great Barrer Reef Marine Park to lesser-known parks in countries such as Thailand and Indonesia, where tourism is placing growing pressures on fragile coral reef systems. As state, national, and international agencies come to recognize the importance of conserving marine biodiversity, marine projected areas whether as sanctuaries,parks, or estuarine reserves, will play an increasingly important role in preserving that diversity.
Question:
According to the passage, when was the National Marine Sanctuaries Program established?

Read the following passage and write the letter A, B, C or D on the top of the first page to indicate the correct answer to each of the questions.

In 1972. a century after the first national park in the United States was established at Yellowstone, legislation was passed to create the National Marine Sanctuaries Program. The intent of this legislation was to provide protection to selected coastal habitats similar to that existing for land areas designated as national parks. The designation of an areas a marine sanctuary indicates that it is a protected area, just as a national park is. People are permitted to visit and observe there, but living organisms and their environments may not be harmed or removed.

The National Marine Sanctuaries Program is administered by the National Oceanic and Atmospheric Administration, a branch of the United States Department of Commerce. Initially, 70 sites were proposed as candidates for sanctuary status. Two and a half decades later, only fifteen sanctuaries had been designated, with half of these established after 1978. They range in size from the very small (less than 1 square kilometer) Fagatele Bay National Marine Sanctuary in American Samoa to the Monterey Bay National Marine Sanctuary in California, extending over 15,744 square kilometers.

The National Marine Sanctuaries Program is a crucial part of new management practices in which whole communities of species, and not just individual species, are offered some degree of protection from habitat degradation and overexploitation. Only in this way can a reasonable degree of marine species diversity be maintained in a setting that also maintains the natural interrelationships that exist among these species.

Several other types of marine protected areas exist in the United States and other countries. The National Estuarine Research Reserve System managed by the United States government, includes 23 designated and protected estuaries. Outside the United States, marine protected-area programs exist as marine parks, reserves and preserves.

Over 100 designated areas exist around the periphery of the Caribbean Sea. Others range from the well-known Australian Great Barrer Reef Marine Park to lesser-known parks in countries such as Thailand and Indonesia, where tourism is placing growing pressures on fragile coral reef systems. As state, national, and international agencies come to recognize the importance of conserving marine biodiversity, marine projected areas whether as sanctuaries,parks, or estuarine reserves, will play an increasingly important role in preserving that diversity.
Question:
The passage mentions the Monterey Bay National Marine Sanctuary in paragraph 2 as an example of a sanctuary that ….

Read the following passage and write the letter A, B, C or D on the top of the first page to indicate the correct answer to each of the questions.

In 1972. a century after the first national park in the United States was established at Yellowstone, legislation was passed to create the National Marine Sanctuaries Program. The intent of this legislation was to provide protection to selected coastal habitats similar to that existing for land areas designated as national parks. The designation of an areas a marine sanctuary indicates that it is a protected area, just as a national park is. People are permitted to visit and observe there, but living organisms and their environments may not be harmed or removed.

The National Marine Sanctuaries Program is administered by the National Oceanic and Atmospheric Administration, a branch of the United States Department of Commerce. Initially, 70 sites were proposed as candidates for sanctuary status. Two and a half decades later, only fifteen sanctuaries had been designated, with half of these established after 1978. They range in size from the very small (less than 1 square kilometer) Fagatele Bay National Marine Sanctuary in American Samoa to the Monterey Bay National Marine Sanctuary in California, extending over 15,744 square kilometers.

The National Marine Sanctuaries Program is a crucial part of new management practices in which whole communities of species, and not just individual species, are offered some degree of protection from habitat degradation and overexploitation. Only in this way can a reasonable degree of marine species diversity be maintained in a setting that also maintains the natural interrelationships that exist among these species.

Several other types of marine protected areas exist in the United States and other countries. The National Estuarine Research Reserve System managed by the United States government, includes 23 designated and protected estuaries. Outside the United States, marine protected-area programs exist as marine parks, reserves and preserves.

Over 100 designated areas exist around the periphery of the Caribbean Sea. Others range from the well-known Australian Great Barrer Reef Marine Park to lesser-known parks in countries such as Thailand and Indonesia, where tourism is placing growing pressures on fragile coral reef systems. As state, national, and international agencies come to recognize the importance of conserving marine biodiversity, marine projected areas whether as sanctuaries,parks, or estuarine reserves, will play an increasingly important role in preserving that diversity.
Question:
The word “administered” the passage is closest in meaning to ……

Read the following passage and write the letter A, B, C or D on the top of the first page to indicate the correct answer to each of the questions.

In 1972. a century after the first national park in the United States was established at Yellowstone, legislation was passed to create the National Marine Sanctuaries Program. The intent of this legislation was to provide protection to selected coastal habitats similar to that existing for land areas designated as national parks. The designation of an areas a marine sanctuary indicates that it is a protected area, just as a national park is. People are permitted to visit and observe there, but living organisms and their environments may not be harmed or removed.

The National Marine Sanctuaries Program is administered by the National Oceanic and Atmospheric Administration, a branch of the United States Department of Commerce. Initially, 70 sites were proposed as candidates for sanctuary status. Two and a half decades later, only fifteen sanctuaries had been designated, with half of these established after 1978. They range in size from the very small (less than 1 square kilometer) Fagatele Bay National Marine Sanctuary in American Samoa to the Monterey Bay National Marine Sanctuary in California, extending over 15,744 square kilometers.

The National Marine Sanctuaries Program is a crucial part of new management practices in which whole communities of species, and not just individual species, are offered some degree of protection from habitat degradation and overexploitation. Only in this way can a reasonable degree of marine species diversity be maintained in a setting that also maintains the natural interrelationships that exist among these species.

Several other types of marine protected areas exist in the United States and other countries. The National Estuarine Research Reserve System managed by the United States government, includes 23 designated and protected estuaries. Outside the United States, marine protected-area programs exist as marine parks, reserves and preserves.

Over 100 designated areas exist around the periphery of the Caribbean Sea. Others range from the well-known Australian Great Barrer Reef Marine Park to lesser-known parks in countries such as Thailand and Indonesia, where tourism is placing growing pressures on fragile coral reef systems. As state, national, and international agencies come to recognize the importance of conserving marine biodiversity, marine projected areas whether as sanctuaries,parks, or estuarine reserves, will play an increasingly important role in preserving that diversity.
Question:
What does the passage mainly discuss?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.

Life in the Universe

Exobiology is the study of life that originates from outside of Earth. As yet, of course, no such life forms have been found. Exobiologists, however, have done important work in the theoretical study of where life is most likely to evolve, and what those extrateưestrial life forms might be like.

What sorts of planets are most likely to develop life? Most scientists agree that a habitable planet must be terrestrial, or rock-based, with liquid surface water and biogeochemical cycles that somewhat resemble Earth’s. Water is an important solvent involved in many biological processes. Biogeochemical cycles are the continuous movement and transformation of materials in the environment. These cycles include the circulation of elements and nutrients upon which life and the Earth’s climate depend. Since (as far as we know) all life is carbon-based, a stable carbon cycle is especially important.

The habitable zone is the region around a star in which planets can develop life. Assuming the need for liquid surface water, it follows that most stars around the size of our sun will be able to sustain habitable zones for billions of years. Stars that are larger than the sun are much hotter and bum out more quickly; life there may not have enough time to evolve. Stars that are smaller than the sun have different problem. First of all, planets in their habitable zones will be so close to the star that they will be “tidally locked” – that is one side of the planet will always face the star in perpetual daylight with the other side in the perpetual night. Another possible obstacle to life on smaller stars is that they tend to vary in their luminosity, or brightness, due to flares and “star spots”. The variation can be large enough to have harmful effects on the ecosystem.

Of course, not all stars of the right size will give rise to life; they also must have terrestrial planets with the right kind of orbits. Most solar systems have more than one planet, which influence each other’s orbits with their own gravity. Therefore, in order to have a stable system with no planets flying out into space, the orbits must be a good distance from one another. Interestingly, the amount of space needed is roughly the width of a star’s habitable zone. This means that for life to evolve, the largest possible number of life-supporting planets in any star’s habitable zone is two.

Finally, not all planets meeting the above conditions will necessarily develop life. One major threat is large, frequent asteroid and comet impacts, which will wipe out life each time it tries to evolve. The case of Earth teaches that having large gas giants, such as Saturn and Jupiter,.in the outer part of the solar system can help keep a planet safe for life. Due to their strong gravitation, they tend to catch or deflect large objects before they can reach Earth.
Question:
Which of the following best expresses the essential information in the highlighted sentence in the passage?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.

Life in the Universe

Exobiology is the study of life that originates from outside of Earth. As yet, of course, no such life forms have been found. Exobiologists, however, have done important work in the theoretical study of where life is most likely to evolve, and what those extrateưestrial life forms might be like.

What sorts of planets are most likely to develop life? Most scientists agree that a habitable planet must be terrestrial, or rock-based, with liquid surface water and biogeochemical cycles that somewhat resemble Earth’s. Water is an important solvent involved in many biological processes. Biogeochemical cycles are the continuous movement and transformation of materials in the environment. These cycles include the circulation of elements and nutrients upon which life and the Earth’s climate depend. Since (as far as we know) all life is carbon-based, a stable carbon cycle is especially important.

The habitable zone is the region around a star in which planets can develop life. Assuming the need for liquid surface water, it follows that most stars around the size of our sun will be able to sustain habitable zones for billions of years. Stars that are larger than the sun are much hotter and bum out more quickly; life there may not have enough time to evolve. Stars that are smaller than the sun have different problem. First of all, planets in their habitable zones will be so close to the star that they will be “tidally locked” – that is one side of the planet will always face the star in perpetual daylight with the other side in the perpetual night. Another possible obstacle to life on smaller stars is that they tend to vary in their luminosity, or brightness, due to flares and “star spots”. The variation can be large enough to have harmful effects on the ecosystem.

Of course, not all stars of the right size will give rise to life; they also must have terrestrial planets with the right kind of orbits. Most solar systems have more than one planet, which influence each other’s orbits with their own gravity. Therefore, in order to have a stable system with no planets flying out into space, the orbits must be a good distance from one another. Interestingly, the amount of space needed is roughly the width of a star’s habitable zone. This means that for life to evolve, the largest possible number of life-supporting planets in any star’s habitable zone is two.

Finally, not all planets meeting the above conditions will necessarily develop life. One major threat is large, frequent asteroid and comet impacts, which will wipe out life each time it tries to evolve. The case of Earth teaches that having large gas giants, such as Saturn and Jupiter,.in the outer part of the solar system can help keep a planet safe for life. Due to their strong gravitation, they tend to catch or deflect large objects before they can reach Earth.
Question:
It can be inferred from paragraph 4 that

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.

Life in the Universe

Exobiology is the study of life that originates from outside of Earth. As yet, of course, no such life forms have been found. Exobiologists, however, have done important work in the theoretical study of where life is most likely to evolve, and what those extrateưestrial life forms might be like.

What sorts of planets are most likely to develop life? Most scientists agree that a habitable planet must be terrestrial, or rock-based, with liquid surface water and biogeochemical cycles that somewhat resemble Earth’s. Water is an important solvent involved in many biological processes. Biogeochemical cycles are the continuous movement and transformation of materials in the environment. These cycles include the circulation of elements and nutrients upon which life and the Earth’s climate depend. Since (as far as we know) all life is carbon-based, a stable carbon cycle is especially important.

The habitable zone is the region around a star in which planets can develop life. Assuming the need for liquid surface water, it follows that most stars around the size of our sun will be able to sustain habitable zones for billions of years. Stars that are larger than the sun are much hotter and bum out more quickly; life there may not have enough time to evolve. Stars that are smaller than the sun have different problem. First of all, planets in their habitable zones will be so close to the star that they will be “tidally locked” – that is one side of the planet will always face the star in perpetual daylight with the other side in the perpetual night. Another possible obstacle to life on smaller stars is that they tend to vary in their luminosity, or brightness, due to flares and “star spots”. The variation can be large enough to have harmful effects on the ecosystem.

Of course, not all stars of the right size will give rise to life; they also must have terrestrial planets with the right kind of orbits. Most solar systems have more than one planet, which influence each other’s orbits with their own gravity. Therefore, in order to have a stable system with no planets flying out into space, the orbits must be a good distance from one another. Interestingly, the amount of space needed is roughly the width of a star’s habitable zone. This means that for life to evolve, the largest possible number of life-supporting planets in any star’s habitable zone is two.

Finally, not all planets meeting the above conditions will necessarily develop life. One major threat is large, frequent asteroid and comet impacts, which will wipe out life each time it tries to evolve. The case of Earth teaches that having large gas giants, such as Saturn and Jupiter,.in the outer part of the solar system can help keep a planet safe for life. Due to their strong gravitation, they tend to catch or deflect large objects before they can reach Earth.
Question:
In order for life to develop, a planet’s orbit must not be

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.

Life in the Universe

Exobiology is the study of life that originates from outside of Earth. As yet, of course, no such life forms have been found. Exobiologists, however, have done important work in the theoretical study of where life is most likely to evolve, and what those extrateưestrial life forms might be like.

What sorts of planets are most likely to develop life? Most scientists agree that a habitable planet must be terrestrial, or rock-based, with liquid surface water and biogeochemical cycles that somewhat resemble Earth’s. Water is an important solvent involved in many biological processes. Biogeochemical cycles are the continuous movement and transformation of materials in the environment. These cycles include the circulation of elements and nutrients upon which life and the Earth’s climate depend. Since (as far as we know) all life is carbon-based, a stable carbon cycle is especially important.

The habitable zone is the region around a star in which planets can develop life. Assuming the need for liquid surface water, it follows that most stars around the size of our sun will be able to sustain habitable zones for billions of years. Stars that are larger than the sun are much hotter and bum out more quickly; life there may not have enough time to evolve. Stars that are smaller than the sun have different problem. First of all, planets in their habitable zones will be so close to the star that they will be “tidally locked” – that is one side of the planet will always face the star in perpetual daylight with the other side in the perpetual night. Another possible obstacle to life on smaller stars is that they tend to vary in their luminosity, or brightness, due to flares and “star spots”. The variation can be large enough to have harmful effects on the ecosystem.

Of course, not all stars of the right size will give rise to life; they also must have terrestrial planets with the right kind of orbits. Most solar systems have more than one planet, which influence each other’s orbits with their own gravity. Therefore, in order to have a stable system with no planets flying out into space, the orbits must be a good distance from one another. Interestingly, the amount of space needed is roughly the width of a star’s habitable zone. This means that for life to evolve, the largest possible number of life-supporting planets in any star’s habitable zone is two.

Finally, not all planets meeting the above conditions will necessarily develop life. One major threat is large, frequent asteroid and comet impacts, which will wipe out life each time it tries to evolve. The case of Earth teaches that having large gas giants, such as Saturn and Jupiter,.in the outer part of the solar system can help keep a planet safe for life. Due to their strong gravitation, they tend to catch or deflect large objects before they can reach Earth.
Question:
The word “sustain” in paragraph 3 could best be replaced by

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.

Life in the Universe

Exobiology is the study of life that originates from outside of Earth. As yet, of course, no such life forms have been found. Exobiologists, however, have done important work in the theoretical study of where life is most likely to evolve, and what those extrateưestrial life forms might be like.

What sorts of planets are most likely to develop life? Most scientists agree that a habitable planet must be terrestrial, or rock-based, with liquid surface water and biogeochemical cycles that somewhat resemble Earth’s. Water is an important solvent involved in many biological processes. Biogeochemical cycles are the continuous movement and transformation of materials in the environment. These cycles include the circulation of elements and nutrients upon which life and the Earth’s climate depend. Since (as far as we know) all life is carbon-based, a stable carbon cycle is especially important.

The habitable zone is the region around a star in which planets can develop life. Assuming the need for liquid surface water, it follows that most stars around the size of our sun will be able to sustain habitable zones for billions of years. Stars that are larger than the sun are much hotter and bum out more quickly; life there may not have enough time to evolve. Stars that are smaller than the sun have different problem. First of all, planets in their habitable zones will be so close to the star that they will be “tidally locked” – that is one side of the planet will always face the star in perpetual daylight with the other side in the perpetual night. Another possible obstacle to life on smaller stars is that they tend to vary in their luminosity, or brightness, due to flares and “star spots”. The variation can be large enough to have harmful effects on the ecosystem.

Of course, not all stars of the right size will give rise to life; they also must have terrestrial planets with the right kind of orbits. Most solar systems have more than one planet, which influence each other’s orbits with their own gravity. Therefore, in order to have a stable system with no planets flying out into space, the orbits must be a good distance from one another. Interestingly, the amount of space needed is roughly the width of a star’s habitable zone. This means that for life to evolve, the largest possible number of life-supporting planets in any star’s habitable zone is two.

Finally, not all planets meeting the above conditions will necessarily develop life. One major threat is large, frequent asteroid and comet impacts, which will wipe out life each time it tries to evolve. The case of Earth teaches that having large gas giants, such as Saturn and Jupiter,.in the outer part of the solar system can help keep a planet safe for life. Due to their strong gravitation, they tend to catch or deflect large objects before they can reach Earth.
Question:
It can be inferred from paragraph 3 that

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.

Life in the Universe

Exobiology is the study of life that originates from outside of Earth. As yet, of course, no such life forms have been found. Exobiologists, however, have done important work in the theoretical study of where life is most likely to evolve, and what those extrateưestrial life forms might be like.

What sorts of planets are most likely to develop life? Most scientists agree that a habitable planet must be terrestrial, or rock-based, with liquid surface water and biogeochemical cycles that somewhat resemble Earth’s. Water is an important solvent involved in many biological processes. Biogeochemical cycles are the continuous movement and transformation of materials in the environment. These cycles include the circulation of elements and nutrients upon which life and the Earth’s climate depend. Since (as far as we know) all life is carbon-based, a stable carbon cycle is especially important.

The habitable zone is the region around a star in which planets can develop life. Assuming the need for liquid surface water, it follows that most stars around the size of our sun will be able to sustain habitable zones for billions of years. Stars that are larger than the sun are much hotter and bum out more quickly; life there may not have enough time to evolve. Stars that are smaller than the sun have different problem. First of all, planets in their habitable zones will be so close to the star that they will be “tidally locked” – that is one side of the planet will always face the star in perpetual daylight with the other side in the perpetual night. Another possible obstacle to life on smaller stars is that they tend to vary in their luminosity, or brightness, due to flares and “star spots”. The variation can be large enough to have harmful effects on the ecosystem.

Of course, not all stars of the right size will give rise to life; they also must have terrestrial planets with the right kind of orbits. Most solar systems have more than one planet, which influence each other’s orbits with their own gravity. Therefore, in order to have a stable system with no planets flying out into space, the orbits must be a good distance from one another. Interestingly, the amount of space needed is roughly the width of a star’s habitable zone. This means that for life to evolve, the largest possible number of life-supporting planets in any star’s habitable zone is two.

Finally, not all planets meeting the above conditions will necessarily develop life. One major threat is large, frequent asteroid and comet impacts, which will wipe out life each time it tries to evolve. The case of Earth teaches that having large gas giants, such as Saturn and Jupiter,.in the outer part of the solar system can help keep a planet safe for life. Due to their strong gravitation, they tend to catch or deflect large objects before they can reach Earth.
Question:
The word “which” in paragraph 3 refers to

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.

Life in the Universe

Exobiology is the study of life that originates from outside of Earth. As yet, of course, no such life forms have been found. Exobiologists, however, have done important work in the theoretical study of where life is most likely to evolve, and what those extrateưestrial life forms might be like.

What sorts of planets are most likely to develop life? Most scientists agree that a habitable planet must be terrestrial, or rock-based, with liquid surface water and biogeochemical cycles that somewhat resemble Earth’s. Water is an important solvent involved in many biological processes. Biogeochemical cycles are the continuous movement and transformation of materials in the environment. These cycles include the circulation of elements and nutrients upon which life and the Earth’s climate depend. Since (as far as we know) all life is carbon-based, a stable carbon cycle is especially important.

The habitable zone is the region around a star in which planets can develop life. Assuming the need for liquid surface water, it follows that most stars around the size of our sun will be able to sustain habitable zones for billions of years. Stars that are larger than the sun are much hotter and bum out more quickly; life there may not have enough time to evolve. Stars that are smaller than the sun have different problem. First of all, planets in their habitable zones will be so close to the star that they will be “tidally locked” – that is one side of the planet will always face the star in perpetual daylight with the other side in the perpetual night. Another possible obstacle to life on smaller stars is that they tend to vary in their luminosity, or brightness, due to flares and “star spots”. The variation can be large enough to have harmful effects on the ecosystem.

Of course, not all stars of the right size will give rise to life; they also must have terrestrial planets with the right kind of orbits. Most solar systems have more than one planet, which influence each other’s orbits with their own gravity. Therefore, in order to have a stable system with no planets flying out into space, the orbits must be a good distance from one another. Interestingly, the amount of space needed is roughly the width of a star’s habitable zone. This means that for life to evolve, the largest possible number of life-supporting planets in any star’s habitable zone is two.

Finally, not all planets meeting the above conditions will necessarily develop life. One major threat is large, frequent asteroid and comet impacts, which will wipe out life each time it tries to evolve. The case of Earth teaches that having large gas giants, such as Saturn and Jupiter,.in the outer part of the solar system can help keep a planet safe for life. Due to their strong gravitation, they tend to catch or deflect large objects before they can reach Earth.
Question:
All of the following are mentioned in the passage as necessary for the development of life except

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.

Life in the Universe

Exobiology is the study of life that originates from outside of Earth. As yet, of course, no such life forms have been found. Exobiologists, however, have done important work in the theoretical study of where life is most likely to evolve, and what those extrateưestrial life forms might be like.

What sorts of planets are most likely to develop life? Most scientists agree that a habitable planet must be terrestrial, or rock-based, with liquid surface water and biogeochemical cycles that somewhat resemble Earth’s. Water is an important solvent involved in many biological processes. Biogeochemical cycles are the continuous movement and transformation of materials in the environment. These cycles include the circulation of elements and nutrients upon which life and the Earth’s climate depend. Since (as far as we know) all life is carbon-based, a stable carbon cycle is especially important.

The habitable zone is the region around a star in which planets can develop life. Assuming the need for liquid surface water, it follows that most stars around the size of our sun will be able to sustain habitable zones for billions of years. Stars that are larger than the sun are much hotter and bum out more quickly; life there may not have enough time to evolve. Stars that are smaller than the sun have different problem. First of all, planets in their habitable zones will be so close to the star that they will be “tidally locked” – that is one side of the planet will always face the star in perpetual daylight with the other side in the perpetual night. Another possible obstacle to life on smaller stars is that they tend to vary in their luminosity, or brightness, due to flares and “star spots”. The variation can be large enough to have harmful effects on the ecosystem.

Of course, not all stars of the right size will give rise to life; they also must have terrestrial planets with the right kind of orbits. Most solar systems have more than one planet, which influence each other’s orbits with their own gravity. Therefore, in order to have a stable system with no planets flying out into space, the orbits must be a good distance from one another. Interestingly, the amount of space needed is roughly the width of a star’s habitable zone. This means that for life to evolve, the largest possible number of life-supporting planets in any star’s habitable zone is two.

Finally, not all planets meeting the above conditions will necessarily develop life. One major threat is large, frequent asteroid and comet impacts, which will wipe out life each time it tries to evolve. The case of Earth teaches that having large gas giants, such as Saturn and Jupiter,.in the outer part of the solar system can help keep a planet safe for life. Due to their strong gravitation, they tend to catch or deflect large objects before they can reach Earth.
Question:
What is the topic of the passage?