30。Though subject to the same wild-animal control efforts that killed off almost all the wolves in North America over the past century, the coyote’s amazing ability of adapting to the presence of humans has enabled it to expend its range into Alaska and Central America.

1. coyote’s amazing ability of adapting to the presence of humans has enabled it to expend its

2. coyote, because of its amazing ability of adapting to the presence of humans, have been able to expand their

3. coyote, because of its amazing ability to adapt to the presence of humans, has been able to expand its

4. amazing ability of the coyote to adapt to the presence of humans have enabled it to expand the      逻辑错误
       

5. amazing ability of the coyote to adapt to the presence of humans has enabled it to expand the
       

偶觉得选A，答案是B。明显错误啊？大家意见？查了讨论贴发现彼GWD-6-30题非此题，故请教诸位同学了

A -- "enabled it to expend its"  , coyote 应该是个种群 ,所以代词用复数才对 　them , their

我觉得只能选C,只有C中代词所对应的单复数一致

coyote->its->has->its

(coyote是只能用复数马？那么上面的分析就不成立了，本题也就没有合适的答案了）