Why, you may wonder, should spiders be our friends? Because they destroy so many insects, and insects 1 some of the greatest enemies of the human race. Insects would make 2 impossible for us to live in the world. They would devour (eat up quickly) all our crops and kill our flocks and herds, were it not 3 the protection we get from insect-eating animals. We 4 a lot to the birds and beasts who eat insects but all of them 5 together kill only a fraction of the 6 destroyed by spiders. 7 , unlike some of the insect eaters, spiders never do the least 8 to us or our belongings.

Spiders are not insects, 9 many people think, 10 even nearly related to them. One can tell the 11 almost at a glance, 12 a spider always has eight legs but an insect never more than six.

How many spiders are 13 in this work on our 14 ? One authority 15 spiders made a 16 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 17 like 6000 000 spiders of different kinds on a football field. Spiders are busy for at least half the year in killing insects. It is 18 to make more than the 19 guess at how many they kill, but they are hungry creature, not 20 with only three meals a day.

1. A. includeB. involveC. consistD. cover

2. A. thisB. that C. itD. them

3. A. withB. forC. ofD. on

4. A. devoteB. dedicateC. oweD. contribute

5. A. gottenB. putC. linkedD. associated

6. A. numberB. amountC. plentyD. proportion

7. A. ConsequentlyB. MoreoverC. ConverselyD. However

8. A. damageB. ruinC. goodD. harm

9. A. asB. whichC. becauseD. though

10. A. soB. eitherC. norD. none

11. A. likenessB. differenceC. similarityD. appearance

12. A. ifB. althoughC. forD. when

13. A. participatedB. joinedC. enclosedD. involved

14. A. honorB. sakeC. sideD. behalf

15. A. onB. inC. aboutD. with

16. A. censusB. consensusC. conscienceD. consciousness

17. A. nothingB. somethingC. anythingD. everything

18. A. likelyB. uselessC. impossibleD. probable

19. A. broadestB. widestC. bravestD. wildest

20. A. concernedB. identifiedC. patientD. content

　　参考答案:ACBCB,ABDAC;BCDDA,ABCDD