CR Bible 全面总结！！！！！！！！！！

puguiyu

谢谢~~~~~~~~~

rikukawa

太感谢！目前觉得CR最要命！

sunxiaoye

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364038310

谢谢楼主

babybearsy

thx~~~~~~~~~~~~~~~~~~~~~~~

kevinzhaoyj

The prairie vole, a small North American grassland rodent, breeds year-round, and a group of voles living together consists primarily of an extended family, often including two or more litters. Voles commonly live in large groups from late autumn through winter; from spring through early autumn, however, most voles live in far smaller groups. The seasonal variation in group size can probably be explained by a seasonal variation in mortality among young voles.

Which of the following, if true, provides the strongest support for the explanation offered?

A It is in the spring and early summer that prairie vole communities generally contain the highest proportion of young voles.

B Prairie vole populations vary dramatically in size from year to year.

C The prairie vole subsists primarily on broad-leaved plants that are abundant only in spring.

D Winters in the prairie voles' habitat are often harsh, with temperatures that drop well below freezing.  

E Snakes, a major predator of young prairie voles, are active only from spring through early autumn.

ae09096

感谢楼主！

Lifeisachoice

thanks a lot

a31314431

13135564y7464

小草吧唧

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