新概念英语4册第2课

Spare that Spider

Why, you may wonder, should spiders be our friends? Because they destory so many instects, and instcts include some of the greatest enemies of the human race. Insects would make it impossible for us to live in the world; they would devour all our crops and kill our flocks and herds, if it were not for the protection we get from insect-eating animals. We owe a lot to the birds and beasts who eat insects but all of them put together kill only a fraction of the number destroyed by spiders. Moreover, unlike some of the other inset eaters, spiders never do the least harm to us or our belongings.

Spiders are not insects, as many people think, nor even nearly related to them. One can tell the difference almost at a glance for a spider always has eight legs and an insect never mor than six.

How many spiders are engaged in this work on our behalf? One authority on spiders made a census of the spiders in a grass field in the south of England, and he estimated that there were more than 2,250,000 in one acre, that is something like 6,000,000 spiders of different kinds on a football pitch. Spiders are busy for at least half the year in killing insect. It is impossible to make more than the wildest guess at how many they kill, but they are hungry creatures, not content with only three meals a day. It has been estimated that the weight of all the insects destroyed by spiders in Britain in one year would be greater than the total weight of all te human beings in the country.

也许你会感到惊奇，为什么蜘蛛会是我们的朋友？因为他们消灭大量的昆虫，而且包括那些对人类有很大

危害的昆虫。如果我们没有那些以昆虫为食的动物的保护，昆虫会使我们无法在这个世界上生活；他们会

破坏所有的庄稼并杀死我们的羊群和牛群。我们对吃昆虫的鸟类和野兽大加赞赏，但是他们合起来只不过

是蜘蛛所消灭昆虫的一部分。此外，不象其他的昆虫吞食者，蜘蛛不会对我们自己或者环境造成一点点的

危害。

象很多人以为的那样，蜘蛛不是昆虫，甚至和它们没有一点联系。仅仅从外观上也能看出差别：蜘蛛总是

有八条腿，而昆虫不会多于六条腿。

有多少蜘蛛在进行会给我们带来益处的工作？一位研究蜘蛛的权威对英格兰南部草原上的蜘蛛进行了种群

普查，他估计每平方公里有2,250,000只，相当于在足球场大小的面积上有6,000,000种不同种类的蜘蛛。

蜘蛛每年至少有一半时间忙于捕食昆虫。除了猜测，无法了解他们究竟捕食多少昆虫。但他们是饥饿的动

物，不满足于一日三餐。据估计英国每年被蜘蛛捕食的昆虫的总重量比整个国家人的重量综合还要多。