职称英语理工类阅读理解备考之精选练习(3)

　　A team of scientists that studied chimpanzees trained to use treadmills has gathered new evidence suggesting that our earliest apelike ancestors started walking on two legs because it required less energy than getting around on all fours. 　　The five chimps also wore face masks used to help the researchers measure oxygen consumption. While the chimps worked out, the scientists collected data that allowed them to calculate which method of locomotion used less energy and why. The team gathered the same information for four adult humans walking on a treadmill. 　　We were prepared to find that all of the chimps used more energy walking on two legs-but that finding wouldnt have been as interesting, Sockol said. what we found was much more telling. For three chimps, bipedalism was more expensive, but for the other two chimps, this wasnt the case. One spent about the same energy walking on two legs as on all fours The other used less energy walking upright。 These two chimps had different gaits and anatomy than their quadrupedal peers. 　　Fossil and molecular evidence suggests the earliest ancestors of the human family lived in forested areas in equatorial Africa in the late Miocene era some 8 to 10 million years ago, when changes in climate may have increased the distance between food patches~ That would have forced our earliest ancestors to travel longer distances on the ground and favored those who could cover more ground using less energy. 　　41. Michael Sockol and his team were interested in 　　B. how chimpanzees could be trained to use treadmills. 　　D. why our apelike ancestors came to walk on two legs. 　　A. calculated. B. exercised. 　　43. What did the researchers find in the experiment? 　　B. Human walking used more energy than bipedal walking in chimps. 　　D. Three chimps used less energy walking on two legs. 　　A. creatures with four feet. B. creatures with two feet. 　　45. What does fossil and molecular evidence tell us about our earliest ancestors? 　　B. They were forced to travel between food patches. 　　D. They were much taller than modern man