练 习 四
　　Directions: There are 20 blanks in the following passage. For each blank there are four choices marked A), B1), B) and D) on the right side of the paper. You should choose the ONE that best fits into the passage. Then mark the corresponding letter in the Answer Sheet with a single line through the center.

　　Nobody likes insects. They are 1 and sometimes dangerous. Some of them bite us and give us 2 ; others bite us and give
　　us big red 3 . Some do not bite, 4 they just fly round our heads or crawl around our houses and gardens. And we don not like any of them 5 those lovely butterflies.
　　But insets are interesting. First, they are very 6 animals. Three hundred and twenty million years ago there were no men and other 7 in the world but there were insects. Today, 8 every square mile of land there are millions of them flying and crawling 9 . Second, insects are very 10 to their habitat, to their food and to the weather. Now there are about a million different 11 in the world. Then 12 do people use insecticides?
　　Not many insects 13 us. In many cases we do not see the insects and we don not think much about them. The 14 is that insects eat so much of man’s food, 15 there are so many billions of them. So we must use insecticides to 16 them.
　　An insecticides is simply a special chemical 17 with some poisonous elements. Farmers 18 their crops very often and the insects die very quickly. Of course some poisonous chemicals 19 on the crops or in the 20, and that is also dangerous to our health.
　　1. A)wicked B) troubling C)exciting D)annoying
　　2. A)wounds B)illness C)diseases D)sickenss
　　3. A)places B)spots C)points D)scraps
　　4. A)and B)or C)but D)for
　　5. A)besides B)including C)but D)except
　　6. A)old B)small C)delicate D)weak
　　7. A)mammals B) reptiles C)cats D)birds
　　8. A)on B)throughout C)with D)in
　　9. A)over B)about C)above D)up
　　10. A)suitable B)agreeable C)adaptable D)changeable
　　11. A)species B)models C)samples D)examples
　　12. A)when B)where C)how D)why
　　13. A)stab B)hurt C)wound D)pin
　　14. A)difference B) method C)condition D)reason
　　15. A)so B)and C)or D)for
　　16. A)put an end to B)get rid of C)take care of D)get hold of
　　17. A)medicine B)compound C)sections D)material
　　18. A)spray B)clean C)cover D)splash
　　19. A)drop B)stay C)disappear D) leave
　　20. A)soil B)earth C)dirt D)mud