Reading Comprehension

试题详情

文章:

    The sloth bear, an insect-eating animal native to Nepal, exhibits only one behavior that is truly distinct from that of other bear species: the females carry their cubs (at least part-time) until the cubs are about nine months old, even though the cubs can walk on their own at six months. Cub-carrying also occurs among some other myrmecophagous (ant-eating) mammals; therefore, one explanation is that cub-carrying is necessitated by myrmecophagy, since myrmecophagy entails a low metabolic rate and high energy expenditure in walking between food patches. However, although polar bears' locomotion is similarly inefficient, polar bear cubs walk along with their mother. 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.

    An alternative explanation is defense from predation. Black bear cubs use trees for defense, whereas brown bears and polar bears, which regularly inhabit treeless environments, rely on aggression to protect their cubs. Like brown bears and polar bears (and unlike other myrmecophagous mammals, which are noted for their passivity), sloth bears are easily provoked to aggression. Sloth bears also have relatively large canine teeth, which appear to be more functional for fighting than for foraging. Like brown bears and polar bears, sloth bears may have evolved in an environment with few trees. They are especially attracted to food-rich grasslands; although few grasslands persist today on the Indian subcontinent, this type of habitat was once widespread there. Grasslands support high densities of tigers, which fight and sometimes kill sloth bears; sloth bears also coexist with and have been killed by tree-climbing leopards, and are often confronted and chased by rhinoceroses and elephants, which can topple trees. Collectively these factors probably selected against tree-climbing as a defensive strategy for sloth bear cubs. Because sloth bears are smaller than brown and polar bears and are under greater threat from dangerous animals, they may have adopted the extra precaution of carrying their cubs. Although cub-carrying may also be adoptive for myrmecophagous foraging, the behavior of sloth bear cubs, which climb on their mother's back at the first sign of danger, suggests that predation was a key stimulus.

题目:

The author mentions rhinoceroses and elephants (in the highlighted text) primarily in order to

选项:

A、explain why sloth bears are not successful foragers in grassland habitats
B、identify the predators that have had the most influence on the behavior of sloth bears
C、suggest a possible reason that sloth bear cubs do not use tree-climbing as a defense
D、provide examples of predators that were once widespread across the Indian subcontinent
E、defend the assertion that sloth bears are under greater threat from dangerous animals than are other bear species

答案:

C

提问:

這道題我首先排除ABD 和slot bear的被狩獵的處境沒有關係 然後糾結於C 和 E E這裏面定位到 Because sloth bears are smaller than brown and polar bears and are under greater threat from dangerous animals, they may have adopted the extra precaution of carrying their cubs. 這裏的 dangerous animals 就包括了 rhinoceroses and elephants 所以選了 E C的話感覺有一些小問題。 Collectively these factors probably selected against tree-climbing as a defensive strategy for sloth bear cubs.這裏定位到 sloth bears also coexist with and have been killed by tree-climbing leopards, and are often confronted and chased by rhinoceroses and elephants。 如果highlight的是leopards 的話我會選C, 但是 rhinoceroses and elephants 不會爬樹呀, 他只是confronted and chased slot bear。 tree-climbing 這兩個動物沒有關係。而且and are often 也説明leopards 和 rhinoceroses and elephants 是并列關係并不是因爲被追著打不得不去爬樹 然後樹上也有leopards 。 請問我這個邏輯有什麽問題麽?
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提问:

这个题问的是目的,我想听下老师的思路 因为前后我都读了 虽然选对 但有点慢,谢谢老师
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提问:

问的是in order to 就往前往后 最后选了正确答案但是选的很慢
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