According to the best evidence gathered by space probes and astronomers, Mars is an inhospitable planet, more similar to Earth's Moon than to Earth itself - a dry, stark, seemingly lifeless world. Mars' air pressure is equal to Earth's at an altitude of 100,000 feet. The air there is 95 percent carbon dioxide.

Mars has no ozone layer to screen out the sun's lethal radiation. Daytime temperatures may reach above freezing, but because the planet is blanketed by the mere wisp of an atmosphere, the heat radiates back into space. Even at the equator, the temperature drops to -50C (-60F) at night. Today there is no liquid water, although valleys and channels on the surface show evidence of having been carved by running water. The polar ice caps are made of frozen water and carbon dioxide, and water may be frozen in the ground as permafrost.

Despite these difficult conditions, certain scientists believe that there is a possibility of transforming Mars into a more Earth-like planet. Nuclear reactors might be used to melt frozen gases and eventually build up the atmosphere. This in turn could create a "greenhouse effect" that would stop heat from radiating back into space. Liquid water could be thawed to form a polar ocean. Once enough ice has melted, suitable plants could be introduced to build up the level of oxygen in the atmosphere so that, in time, the planet would support animal life from Earth and even permanent human colonies. "This was once thought to be so far in the future as to be irrelevant," said Christopher McKay, a research scientist at NASA. "But now it's starting to look practical. We could begin work in four or five decades."

The idea of "terra-forming" Mars, as enthusiasts call it, has its roots in science fiction. But as researchers develop a more profound understanding of how Earth's ecology supports life, they have begun to see how it may be possible to create similar conditions on Mars. Don't plan on homesteading on Mars any time soon, though. The process could take hundreds or even thousands of years to complete and the cost would be staggering.

According to Christopher McKay, the possibility of transforming Mars

The Boeing 747 is twice ____the Boeing 707.

The culture has been_____ with the arrival of immigrants.

It's very difficult to integrate yourself__ a society where culture is so different from your own

According to the best evidence gathered by space probes and astronomers, Mars is an inhospitable planet, more similar to Earth's Moon than to Earth itself - a dry, stark, seemingly lifeless world. Mars' air pressure is equal to Earth's at an altitude of 100,000 feet. The air there is 95 percent carbon dioxide.

Mars has no ozone layer to screen out the sun's lethal radiation. Daytime temperatures may reach above freezing, but because the planet is blanketed by the mere wisp of an atmosphere, the heat radiates back into space. Even at the equator, the temperature drops to -50C (-60F) at night. Today there is no liquid water, although valleys and channels on the surface show evidence of having been carved by running water. The polar ice caps are made of frozen water and carbon dioxide, and water may be frozen in the ground as permafrost.

Despite these difficult conditions, certain scientists believe that there is a possibility of transforming Mars into a more Earth-like planet. Nuclear reactors might be used to melt frozen gases and eventually build up the atmosphere. This in turn could create a "greenhouse effect" that would stop heat from radiating back into space. Liquid water could be thawed to form a polar ocean. Once enough ice has melted, suitable plants could be introduced to build up the level of oxygen in the atmosphere so that, in time, the planet would support animal life from Earth and even permanent human colonies. "This was once thought to be so far in the future as to be irrelevant," said Christopher McKay, a research scientist at NASA. "But now it's starting to look practical. We could begin work in four or five decades."

The idea of "terra-forming" Mars, as enthusiasts call it, has its roots in science fiction. But as researchers develop a more profound understanding of how Earth's ecology supports life, they have begun to see how it may be possible to create similar conditions on Mars. Don't plan on homesteading on Mars any time soon, though. The process could take hundreds or even thousands of years to complete and the cost would be staggering.

According to the passage, the basic knowledge needed to transform Mars comes from

They_____ any junk mail since they_____ house

He was presented with a gold watch in_____ of his years as club secretary.

While I am waiting at the bus stop, three buses went by in the opposite

                                        A                         B                                     C               D

direction.

Ann: "The book is by T.C.Smith.” -Marie: "What does the T.C.____?"

She stood there,______ over whether or not to tell him the truth.

The other passengers will get on the bus soon. Then we'll leave

Mark the letter A, B, C, or D on your answer sheet to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.

Amy Tan was born on February 19, 1952 in Oakland, California. Tan grew up in Northern California, (41)____when her father and older brother both died from brain tumors in 1966, she moved with her mother and younger brother to Europe, where she attended high school in Montreux, Switzerland. She returned to the United States for college. After college, Tan worked (42)____ a language development consultant and as a corporate freelance writer. In 1985, she wrote the story "Rules of the Game" for a writing workshop, which laid the early (43)_____ for her first novel The Joy Luck Club. Published in 1989, the book explored the (44)____ between Chinese women and their Chinese-American daughters and became the longest-running New York Times bestseller for that year. The Joy Luck Club received numerous awards, including the Los Angeles Times Book Award. It has been translated into 25 languages, including Chinese, and was made into a major motion picture for (45)_____ Tan co-wrote the screenplay. Tan's other works have also been adapted into several different forms of media.

Question 43:

Planes were unable to_____ from Gatwick owing to high winds

Mark the letter A, B, C, or D on your answer sheet to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions.

The Green Party is dedicated to protecting the environment.

I can't believe how much John____ his father. They look and act exactly the same