7. It is not enough only 　　　　the rules of grammar if you want to learn English well.

A. keeping in the mind

B. to keep in mind

C. to keep in your mind

D. keeping in your mind

选B。keep sth. in mind 为固定短语，意为“记住，记在心里。”only to keep sth. In mind为动词不定式作主语。

6. He 　　　　the person referred to be put in prison.

A. said　　　　 B. demanded

C. agreed　　　 D. thought

选B。referred to为过去分词作后置定；be put in prison前省去了should，在宾语从句中作谓语，在四个选项中，只有demand后跟虚拟语气，结构为：(should) + 动词原形。

5.　　 　you I owe a thousand apologies 　　　　

having doubted your ability.

A. For; to　　　　 　B. To; for

C. For; for　　　　 D. To; to

选B。本句的结构是：owe sb. sth. for doing sth. 或owe sth. to do. for doing sth.。

3.　　 , I think, and all the problems could be settled.

A. If you make more efforts

B. Making more efforts

C. A bit more effort

D. To have made more efforts

选C。句中有并列连词and，故应选择C项。其中名词短语相当于一个祈使句，完整的句子为：Make more efforts, I think, and all the problems could be settled.如选A , and要删去。

4 　　　　at in this way, the present situation about birds flue doesn’t seem so disappointing.

　 A. Looking　　　　　 　B. Looked

　 C. Having looked　　 D. To look

选B。根据“分词短语作状语，其逻辑主语须与主句的主语保持一致”的原则，因主语the present situation与look at 之间为被动关系，故答案为B。

2. The TV programme has 　　　　on the children as 　　　as the old.

A. a good effect; good

B. a positive effect; well

C. a good affect; well

D. affect; well

选B。have an effect on“对……有影响”；as well as “和……一样”。

1.It was 　　　　great shock to the world that two aero-planes crashed into 　　　　World Trade Center in New York o September 11th, 2001.

A. a; /　 B. a; the　 C. the; the　　 D. /; the

选B。shock指代具体事情时为可数名词，a great shock意为“一次沉重的打击”；由普通名词构成的建筑类专有名词需加冠词，故答案为B。

20.Children’s brains can’t develop properly_______ they lack protein(蛋白质).

　A. when　 B. since　 C. because　 D. unless

　选A。本题考查when的一个特殊用法。在本题中的when引导的是一个条件状语从句，相当于if。整个句子的意思是：如果孩子缺少蛋白质，大脑就不能正常发育。

19.This is the very toy car ________ which he came here the other day.

　A. by　 B. in　 C. for　 D. on

　选C。容易误选A或B。根据常识，我们知道他是不可能坐toy car到这儿来的。所以选C。用for表示来的目的。

18.---Spacecraft “Discovery” has failed in the course of launch.

　 ----_______? They have been preparing for the test.

　 A. How come　 B. When　 C. How　 D. Why not

　选A。how come在这里的意思是“怎么回事？”，表示不解，惊讶。

17.I began to fish before memory began, _______ I know I have always fished.

　A. so far　 B. so as far as　 C. as far as　 D. so

　 选B。本题中逗号前是一个主从复合句，后面也是主从复合句，因此其间需要一个并列连词，so 是并列连词，B，D两项中有so,如果选D，I know后面的部分成了宾语从句，不符合题意。而B项的so连接两个分句，as far as为I know的从属连接词，故B为正确答案。