Furthermore, the daily movements of sloth bears and American black bears—which are similar in size to sloth bears and have similar-sized home ranges—reveal similar travel rates and distances, suggesting that if black bear cubs are able to keep up with their mother, so too should sloth bear cubs.
Which of the following,if true, would most weaken the author’s argument?
(A) Cub-carrying behavior has been observed in many non-myrmecophagous mammals.
(B) Many of the largest myrmecophagous mammals do not typically exhibit cub-carrying behavior.
(C) Some sloth bears have home ranges that are smaller in size than the average home ranges of black bears.
(D) The locomotion of black bears is significantly more efficient than the locomotion of sloth bears.
(E) The habitat of black bears consists of terrain that is significantly more varied than that of the habitat of sloth bears.
本题问的是哪个选项可以削弱文章的某一部分。有过对付批判性推理考题经验的考生一定可以很快判断出原文是一个“类比推理”，只要能找出懒熊和美国黑熊的不同点就可以找出本题的答案，由此可以快速排除(A)(B)(C)（(C)讲的是某些懒熊的home ranges小于黑熊，这一点原文中讲过两者“相似”，已经包含了某一些懒熊的home ranges较黑熊大，某一些小了）。由于原文的结论讲的是小懒熊是否有能力跟上母懒熊，所以(D)选项与原文更加相关，答案为(D)。