Question

【题目】 Fishing is a popular activity and every fisherman knows the rule: Keep the big ones, throw the smaller ones back. The idea behind it is simple — larger fish are probably older. If you keep the smaller young fish, they won’t be able to reproduce, so there will be fewer fish.

But fishing out the largest fish from a population may also have an unwanted effect: Over time, fewer adult fish get really big. If only the smaller fish reproduce, then future generations become smaller.

One scientist, Dr David Conover has spent the last decade studying the effects of the “keep the big ones” rule.

In his experiment, Conover used six groups of fish. For two groups, Conover followed the “keep the big ones” rule and took out the biggest fish. For two other groups, he removed only the small fish. For the last two groups, he removed fish at random (随意地).

After five years, he measured the fish in each group. In the two groups where the largest fish were regularly removed, the average fish size was smaller than the average size in the other groups. It showed that if only small fish survive to reproduce, then future generations of fish will also tend to be small.

For the second five years of his experiment, Conover changed the rules and took fish randomly from each group. At the end of the experiment, he found that the fish that were in the “keep the big ones” groups for the first five years had started to get larger again, although he calculated it would take at least 12 years for the fish in those two groups to return to their original size.

In other words, it takes much more time to recover.

【1】The underlined word “it” (Paragraph 1) refers to “________”.

A.the activityB.the fish

C.the ruleD.the fisherman

【2】What’s the purpose of the “keep the big ones” rule?

A.It helps to protect fish numbers.

B.It helps to protect fish size.

C.It teaches people how to fish.

D.It helps people catch bigger fish.

【3】After the first five years of his experiment, Conover found the “keep the big ones” rule ______.

A.made no difference to fish size

B.made the fish smaller on average

C.made the fish bigger on average

D.made the fish reproduce more quickly

【4】What is the author’s intention in writing this article?

A.To encourage people to stop fishing.

B.To urge governments to forbid fishing.

C.To describe a scientific experiment about fishing.

D.To introduce the rules of fishing to readers.

Answer 1

【答案】

【1】C

【2】A

【3】B

【4】C

【解析】

这是一篇说明文。文章通过一个实验说明，在捕鱼时，“只留大鱼”的原则的影响。结果证明，如果在捕鱼时“留大鱼；放小鱼”会使得鱼的后代变得越来越小。

【1】词义猜测题。根据文章第一段中Fishing is a popular activity and every fisherman knows the rule: Keep the big ones, throw the smaller ones back. The idea behind it is simple. 钓鱼是一项很受欢迎的活动，每个渔民都知道这个规则:留下大的，把小的扔回去。其背后的想法很简单。由此可知，it指上文中“留大鱼；扔小鱼”的捕鱼规则。故选C。

【2】推理判断题。根据文章第一段中If you keep the smaller young fish, they won’t be able to reproduce, so there will be fewer fish. 如果你留下较小的幼鱼，它们就不能繁殖，因此鱼就会减少。由此可以推测出，“留大鱼”规则的目的是为了保持鱼的数量。故选A。

【3】细节理解题。根据文章倒数第二段中After five years, he measured the fish in each group. In the two groups where the largest fish were regularly removed, the average fish size was smaller than the average size in the other groups. 五年之后，他对每组的鱼进行了测量。在两组定期去除最大的鱼，鱼的平均大小比其他组的平均大小要小。由此可知，经过前五年的实验，Conover发现“保留大鱼”规则会使鱼变小。故选B。

【4】推理判断题。根据文章第三段中One scientist, Dr David Conover has spent the last decade studying the effects of the “keep the big ones” rule. 大卫·科诺弗博士是一位科学家，他在过去十年中一直在研究“保留大鱼”规则的影响。以及分析全文可知，本文的目的主要介绍了关于鱼的一个实验。故选C。