First listen and then answer the following question.
听录音，然后回答以下问题。
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 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 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.
T.H．GILLESPIE Spare that spider from The Listener
New words and expressions生词和短语
beast(1.4) [bi:st]n．野兽
acre(1.11) ['eikə]n．英亩
census(1.9) ['sensəs]n．统计数字
content(1.13) [kən'tent] adj．满足的
Notes on the text课文注释
1you may wonder 是这个疑问句的插入语。
2if it were notfor the protection we get from insect-eating animals，这是一个非真实条件状语从句， were表示虚拟语气。
Refer to the text to see how the following words have been used, then write sentences of your own using these words: destroy (1.1); devour (1.3); fraction (1.5); belongings (1.6); estimated (1.10).
Sentence structure句子结构
A Combine the following sentences to make one complex statement out of each group．Make any changes you think necessary, but do not alter the sense of the original．Do not refer to the passage until you have finished the exercise:
1Moreover, spiders are unlike some of the other insect eaters．They never do the least harm to us or our belongings.(11.5-6)
2Spiders are not insects．They are not even nearly related to them．Many people think they are．(1.7)
3One can tell the difference almost at a glance．A spider has eight legs．An insect never has more than six．(11.7-8)
4How many do they kill? It is impossible to make more than the wildest guess at this．They are hungry creatures.
They are not content with only three meals a day．(11.12-13)
BComplete the following sentences in any way you wish．Thencompare what you have written with the sentences in the passage:
1Why, you may wonder, should spiders be our friends? Because ____．(11.1-2)
2We owe a lot to birds and beasts who ____．(11.4-5)
3One authority on spiders ____．(11.9-10)
4It has been estimated that ____．(11.13-15)
CWrite three sentences saying why you like or dislike spiders.
Key structures关键句型
A Compare these two sentences:
Instead of saying: I wonder why spiders are our friends.
We can say: Why…should spiders be our friends? (1.1)
Write these sentences again using the construction with should in place of the phrases in italics:
1I wonder why he is so disappointed．
2I wonder why you are so unwilling to change your mind．
3I wonder why there are so many traffic accidents.
BNote the form of the verb be in this sentence:
They would devour all our crops if it were not for the protection we get from insect-eating animals.(11.3-4)
Supply the correct form of be in these sentences:
1I certainly wouldn't buy that car if I (be) in your position.
2Do you think you would buy it if it (be) cheaper?
3If I (be) made such an offer I would certainly accept it.
CSupply a, an, and the where necessary in the spaces below．Do not refer to the passage until you have finished the exercise:
____ spiders are not ____ insects, as ____ many people think, nor even nearly related to them.
One can tell ____ difference almost at ____ glance for ____ spider always has eight legs and ____ insect never more than six.
How many spiders are engaged in this work on our behalf? One authority on ____ spiders made ____ census of ____ spiders in ____ grass field in ____ south of ____ England,and he estimated that there were more than 2,250,000 in ____ acre; that is something like 6,000,000 spiders of different kinds on ____ football pitch．(11.7-11)
Special difficulties难点
AStudy the following pairs of words and then write sentences of your own to bring out the difference:
1all…together (11.4-5)----altogether
Let's sing it again．All together now!
As far as I am concerned, Frank's proposal is altogether nonsensical.
2other(1.5)----else
One of these blouses has buttons; the other hasn't.
We need one more helper．Can you find anyone else?
3the least (1.6)----the last
He passed all his exams without seeming to make even the least effort.
She wouldn't marry him even if he was the last man on the planet.
4harm (1.6)----hurt
Fertilizers have done a lot of harm to the soil．The bad effects will last a long time.
I banged my arm against the door and hurt myself．My arm still hurts．It's very painful.
5glance (1.8)----glimpse
Would you mind having a glance at my essay before I hand it in?
I caught a glimpse of him as he walked past my window.
6work (1.9)----job
I'm looking for work as a journalist.
Have you been doing all this work on your own?
I'd like a job in TV．Are there any jobs in TV?
7estimated (1.10)----calculated
I estimate there must be at least eight hundred names on the list.
We've calculated the cost of a new office and it's more than we can afford．
BWhich verbs could be used in place of get in these sentences:
1They would devour all our crops and kill our flocks andherds, if it were not for the protection we get from insecteating animals．(11.2-4)
2I got this hat at the shop on the corner.
3Will you get that book for me please? It's on the shelf.
4I got a letter from my brother yesterday.
5I'm sorry, I didn't get that remark.
6I didn't laugh because I didn't get the joke.
CNote the use of tell in this sentence:
One can tell the difference almost at a glance．(11.7-8)
Supply the correct form of say or tell in these sentences:
1Will you please ____ me the time?
2I'm not very good at ____ stories.
3You must ____ your prayers and go to bed．
4Please ____ nothing more about it.
5I can ____ you something about it.
6We ____ goodbye and left.
7I want you to ____ the truth.
DNote the use of make in this sentence:
One authority on spiders made a census．(11.9-10)
Supply the correct form of make or do in the following sentences:
1I ____ a number of proposals, none of which was accepted．
2I'll ____ the washing up.
3Will you help me to ____ this crossword puzzle?
4You've ____ quite a few mistakes.
5I've ____ an appointment for you for next week.
6They ____ an announcement about it on the radio.
7I'll ____ my best to help you.
EWrite sentences using the following phrases with at:
at a glance (1.8); at least (11.11-12); at any rate; at a loss; at sight; at a time.
Multiple choice questions多项选择题
Choose the correct answers to the following questions.
Comprehension 理解
1Spiders are our friends because they ____.
a．are beneficial insects
b．destroy insects without hurting us in any way
c．protect insect-eating animals
d．include some of the greatest enemies of the human race
2Birds and beasts ____.
a．eat as many insects as spiders
b．eat more insects than spiders
c．can't compare with spiders as destroyers of insects
d．destroy a larger fraction of insects than spiders
3If spiders were insects, they would ____.
a．have eight legs
b．have six legs
c．be able to fly
d．not destroy their own kind
4Spiders are active in killing insects ____.
a．all the time
b．for most of the year
c．in the summer months
d．for a minimum of six months of each year
Structure句型
5It would ____ impossible for us to live in this world if insects had no enemies．(11.2-3)
a．make it
b．stay
c．be
d．have it
6We owe ____ to the birds and beast who eat insects.(1.4)
a．a great deal
b．a lot of
c．a great many
d．much of
7How many spiders are involved ____ this work on our behalf?(1.9)
a．at
b．for
c．in
d．to
8There are many different ____ spiders.(1.11)
a．sorts of
b．kind of
c．type of
d．kinds
Vocabulary词汇
9Spiders ____ insects．(11.3-4)
a．defend us from
b．guard
c．protect
d．insure us against
10You can see at a glance that spiders are not ____ insects.(1.7)
