練習：
    1． What did Michael Sockol and his team find out in their study of chimpanzees?
    A Tile evidence why chimpanzees can be trained to use treadmills．
    B The evidence why our apelike ancestors came to walk on four legs．
    C The evidence why our apelike ancestors came to walk on two legs．
    D The evidence why chimpanzees can be trained to walk on two legs．
    2． Which of the following best interprets the meaning of “While the chimps worked out ．．．． ” (the first sentence of the third paragraph)?
    A While the chimps worked in the lab ．．．
    B While the chimps exercised in the gym ．．．
    C While the chimps tried to figure out what they should do ．．．
    D While the chimps tried to understand the instructions ．．．
    3． What was the result of the finding，according to Paragraph 5?
    A Three chimps used more energy walking on two legs．
    B One chimp used less energy walking on two legs．
    C One chimp used about the same energy walking on two legs as on four．
    D All of the above．
    4． What was true of the hypothesis of the research?
    A Our apelike ancestors were anatomically different but had the same gaits．
    B Bipeds with natural selection had an advantage over quadruped．
    C Our apelike ancestors could adapt to different climate changes due to genetic variation．
    D Bipeds had an advantage over quadrupeds due to changes in the environment．
    5． What does fossil and molecular evidence tell us about our earliest ancestors?
    A They experienced more climate changes than we do today．
    B Due to changes in climate，they were forced to travel between food patches．
    C They could cover more ground than their quadrupedal peers because they used less energy．
    D They could travel longer distances on the ground than those who could use less energy．
    答案與題解：
    1． C 短文的第一段直接回答了這個問題。
    2． B worked out在此是“運動，鍛煉”的意思，所以選擇B。
    3． D 第五段的第三、第四和第五句提供了答案。bipedalism was more expensive的意思是：兩足行走消耗更多的體能。walking upright的意思是：直立行走，即兩足行走。
    4． B 第六段告訴了我們研究的兩個假設：猿人祖先在解剖學意義上存在著差異，這一差異影響了它們的步態(tài)；這些差異在自然選擇的過程中決定了遺傳變異，而環(huán)境變化使得兩足行走的猿人比起四足行走的猿人更有戰(zhàn)勢。A、C、D都不是正確的說法，只有B在該段中被提到。
    5． C 倒數(shù)第二段提供了問題的答案。travel longer distances用的是比較級，這里是將兩足行走的猿人與上文中四足行走的猿人做比較。those who could cover more ground using less energy指的是上文提到的與四足行走的猿人相比，體能消耗較小的兩足行走猿人。其他選擇都不是正確說法。