2014年考研英語新概念必背作文精選： 不要傷害蜘蛛
Lesson 2 Spare that spider不要傷害蜘蛛
Why, you may wonder, should spiders be our friends? Because theydestroy so many insects, and insects include some of the greatest enemies ofthe 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 notfor the protection we get from insect-eating animals.We owe a lot to the birdsand beasts who eat insects but all of them put together kill only a fraction ofthe number destroyed by spiders.Moreover, unlike some of the other insecteaters, spiders never do the least harm to us or our belongings.
Spiders are not insects, as many people think, nor even nearlyrelated to them.One can tell the difference almost at a glance, for a spideralways has eight legs and an insect never more than six.
How many spiders are engaged in this work on our behalf? Oneauthority on spiders made a census of the spiders in a grass field in the southof 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 footballpitch.Spiders are busy for at least half the year in killing insects.It isimpossible to make more than the wildest guess at how many they kill, but theyare hungry creatures, not content with only three meals a day.It has beenestimated that the weight of all the insects destroyed by spiders in Britain inone year would be greater than the total weight of all the human beings in thecountry.
你可能會覺得奇怪，蜘蛛怎么會是我們的朋友呢?因?yàn)樗鼈兡芟麥缒敲炊嗟睦ハx，其中包括一些人類的大敵。要不是人類受一些食蟲動(dòng)物的保護(hù)，昆蟲就會使我們無法在地球上生活下去，昆蟲會吞食我們的全部莊稼，殺死我們的成群的牛羊。我們要十分感謝那些吃昆蟲的鳥和獸，然而把它們所殺死的昆蟲全部加在一起也只相當(dāng)于蜘蛛所消滅的一小部分。此外，蜘蛛不同于其他食蟲動(dòng)物，它們絲毫不危害我們和我們的財(cái)物。
許多人認(rèn)為蜘蛛是昆蟲，但它們不是昆蟲，甚至與昆蟲毫無關(guān)系。人們幾乎一眼就能看出二者的差異，因?yàn)橹┲攵际?條腿，而昆蟲的腿從不超過6條。
有多少蜘蛛在為我們效力呢?一位研究蜘蛛的權(quán)威對英國南部一塊草坪上的蜘蛛作了一次調(diào)查。他估計(jì)每英畝草坪里有225萬多只蜘蛛。這就是說，在一個(gè)足球場上約有600萬只不同種類的蜘蛛。蜘蛛至少有半年忙于吃昆蟲。它們一年中消滅了多少昆蟲，我們簡直無法猜測，它們是吃不飽的動(dòng)物，不滿意一日三餐。據(jù)估計(jì)，在英國蜘蛛一年里所消滅昆蟲的重量超過了這個(gè)國家人口的總重量。
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