2. 外语
  3. Small dogs generally live longer than big dogs so that yappy Yorkshire terrier next door could be around for a long time. But bo

Small dogs generally live longer than big dogs so that yappy Yorkshire terrier next door could be around for a long time. But bo

admin2010-12-04  46
问题     Small dogs generally live longer than big dogs so that yappy Yorkshire terrier next door could be around for a long time. But body size isn’t the only factor that【B1】______how long dogs survive. Personality influences life span, too, according to a new study that might help explain how animal【B2】______evolve.
    Research on animals from ants to apes has found that different【B3】______have different personalities. Some are timid, others【B4】______. Biologists have proposed that temperaments evolved along with life history.【B5】______, violent animals use a lot of energy fast in【B6】______short lives, the thinking goes, whereas calmer animals last longer, saving themselves to【B7】______later in life.
     But it’s hard to run evolutionary【B8】______on these personalities in anything longer lived than a fruit fly. So evolutionary biologist Vincent Careau of Universit6 de Sherbrooke in Canada came up with an idea: dogs. "All these breed differences reflect an experiment on artificial selection," says Careau.【B9】______, but from generations of humans crossbreeding and selecting animals with traits---the ability to chase foxes into holes, or herd sheep, or sit attractively on a sofa.
But evolutionary physiologist Joseph Williams of Ohio State University in Columbus isn’t convinced that【B10】______. "For me, it still remains to be seen. Dogs are contrary to what you would expect in nature in terms of longevity," he says. Elephants live for decades,【B11】______. On the other hand, a Chihuahua will generally outlast a Saint Bernard.
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答案determines
解析 根据句子结构，此处缺少定语从句的谓语，需填入一个可以带宾语从句的动词。
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