新概念英语四第2课-不要伤害蜘蛛

新概念英语四第

2

课

-

不要伤害蜘蛛

How much of each year do spiders spend killing insects?

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 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

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.

【

New words and expressions

生词和短语】

insect n.

昆虫

devour v.

吞食

flock n.

羊群

herd n.

牧群

beast n.

野兽

fraction n.

小部分

census n.

统计数字

acre n.

英亩

content adj.

满足的

【课文注释】

1. you may wonder

是这个疑问句的插入语。

常见的插入语还有：

as you know, to be frank, in fact,

generally speaking

等等。

2. flock

既可作名词，也可作动词。

①作名词，表示羊群或牛群，或者人群

例句：

They kept a small flock of sheep.

他们养了一小群羊。

例句：

There are many flocks of tourists in the palace.

宫殿里有好几群游客。