Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 1 to 5.

SHE STUDIES WHILE HE PLAYS: TRUE OF CHILDREN AND CHIMPS

Chimpanzees in the wild like to snack on termites, and youngsters learn to fish for them by pocking long sticks and other (1)........tools into the mounds that large groups of termites build. Researchers found that (2)............average female chimps in the Gombe National Park in Tanzania learned how to do termite fishing at the age of 31 months, more than two years earlier than the males.

The females seem to learn by watching their mothers. Researcher Dr. Elisabeth V. Lonsdorf, director of field conservation at the Lincoln Park Zoo in Chicago, said that it is (3).............to find that, when a young male and female are near a mound, ‘she’s really focusing on termite fishing and he’s spinning himself round (4)...........circles’. Dr Landsdorf and colleagues are studying chimpanzees at the zoo with a new, specially created termite mound, filled with mustard (5).......than termites.