题干

达尔文在著名的《物种起源》一书中讲了一个饶有兴趣的“猫与牛”的故事。英国的牛主要靠优质的红三叶草为饲料,而红三叶草的兴衰与给它传粉的丸花蜂有很大关系。奇妙的是,丸花蜂的多少,又决定于田鼠的数量,因为田鼠吃蜂房和蜂幼虫,田鼠势旺丸花蜂便衰败。而猫吃田鼠,猫多了,田鼠就少了,丸花蜂就多了,红三叶草就兴盛了,牛就养壮了。一切生物处于普遍联系之中,这是辩证法最基本的观点,表面看起来不相关的生物却盛衰依存,祸福倚伏。
(1) 写出故事中最长的一条食物链:
(2)这个故事说明了一个什么问题?

上一题 下一题 0.0难度 选择题 更新时间:2014-04-29 04:51:20

答案(点此获取答案解析)

(1)红三叶草→丸花蜂→田鼠→猫
(2)自然界的动物和植物在长期生存与发展的过程中,形成了相互适应相互依存的关系。

同类题4

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项,选项中有两项为多余选项。

        If you find that your teacher is unfair to you, think about what is happening. Try to find out whether your teacher really dislikes you, or whether something else is going on. Here are some questions to ask yourself:

        ____Ask your classmates if they are having trouble with the teacher, too. If they say yes, perhaps your teacher is to blame.

        Are you working up to your ability? Maybe you got a C in your last test, and your teacher told you that you could do better. And the kid sitting beside you got a C, too.____Isn't this unfair? Well, it could be that your teacher knows that you could do better if you put more effort into it.____

        ____There's nothing wrong with being sensitive(敏感的),but if you react to criticism quite differently from others, this could be a reason why you think your teacher doesn't like you.

        Does your teacher seem to act unfairly all the time, or just once in a while? Think about the harsh(苛刻的) things your teacher has done to you. Are these things happening every day, or just once or twice a month? If your teacher really hates you, you would probably be picked on all the time.____

A  Are you the only person being treated badly, or is your teacher rough on the whole class?

B  Are you getting along well with your classmates? 

C  Are you more sensitive than other students?

D  Are you interested in your lessons?

E  If your teacher has acted unfairly only a few times, then there's probably something else going on.

F  Teachers often grade students by different standards.

G  But the teacher didn't say anything to him!