14号就考试了，这道题看还不懂诶

HannaJia

Which of the following most logically completes the reasoning?

Either food scarcity or excessive hunting can threaten a population of animals. If the group faces food scarcity, individuals in the group will reach reproductive maturity later than otherwise. If the group faces excessive hunting, individuals that reach reproductive maturity earlier will come to predominate. Therefore, it should be possible to determine whether prehistoric mastodons became extinct because of food scarcity or human hunting, since there are fossilized mastodon remains from both before and after mastodon populations declined, and ______.

A. there are more fossilized mastodon remains from the period before mastodon populations began to decline than from after that period

B. the average age at which mastodons from a given period reached reproductive maturity can be established from their fossilized remains

C. it can be accurately estimated from fossilized remains when mastodons became extinct

D. it is not known when humans first began hunting mastodons

E. climate changes may have gradually reduced the food available to mastodons

alzn2765

B
这题就是一个很简单的道理：食物少的的时候，动物会晚进入性成熟（少生娃跟你抢吃的）；面对过度捕杀的时候，动物会早进入性成熟（用生娃弥补数量的损失）。

为了 determine whether prehistoric mastodons became extinct because of food scarcity or human hunting，就通过化石看动物什么时候进入性成熟期就好了