一篇關於介紹蜘蛛的英語作文
Why, you may wonder, should spiders be our friends? Because they destroy so many insects, and insects 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 insect 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 more 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 insects.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 the human beings in the country.
你可能會覺得奇怪，蜘蛛怎么會是我們的朋友呢?因為它們能消滅那么多的昆蟲，其中包括一些人類的大敵。要不是人類受一些食蟲動物的保護，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於蜘蛛所消滅的一小部分。此外，蜘蛛不同於其他食蟲動物，它們絲毫不危害我們和我們的財物。
許多人認為蜘蛛是昆蟲，但它們不是昆蟲，甚至與昆蟲毫無關係。人們幾乎一眼就能看出二者的差異，因為蜘蛛都是8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?一位研究蜘蛛的權威對英國南部一塊草坪上的蜘蛛作了一次調查。他估計每英畝草坪里有225萬多隻蜘蛛。這就是說，在一個足球場上約有600萬隻不同種類的蜘蛛。蜘蛛至少有半年忙於吃昆蟲。它們一年中消滅了多少昆蟲，我們簡直無法猜測，它們是吃不飽的動物，不滿意一日三餐。據估計，在英國蜘蛛一年裡所消滅昆蟲的重量超過了這個國家人口的總重量。