6. People believe that he is ill.

→　 It is believed that he is ill.

→ He is believed to be ill.

5. They watched the children sing that morning.

→　 The children were watched to sing that morning.

4. The children gave the foreign guests a warm welcome.

→ The foreign guests were given a warm welcome by the children.

3. The boy happened to meet her in the street.

→ She happened to be met in the street by the boy.

2. Different cooks in different parts of China cook dishes in different ways.

→Dishes are cooked in different ways by different cooks in different parts of China.

1. The teacher told the children a story.

→The children were told a story by the teacher.

12. Mr. Brown is one of the few persons I know who______ from experience.

A. has learnt　　　　　　　　　　　　　　 B. have learnt

C. had learnt　　　　　　　　　　　　　　 D. has been learnt

[解析]选B。句意: 据我所知, 布朗先生是极少数向经验学习的几个人之一。one of +复数名词+who定语从句, 先行词persons为复数名词, 从句谓语动词用复数, 且主句的谓语动词为is, 为一般现在时, 因此选B。

11. -Shall I wait here for three hours?

-Yes. Three hours_______ for you to wait for such a doctor.

A. are not very long　　　　　　　　　　　　　　 B. is not long enough　　　

C. was not long enough　　　　　　　　　　　 D. will be too long

[解析]选B。句意: --我要在这等三个小时吗? --是的。对你来说等这样一位医生花三个小时并不算长。表示金钱、时间、价格或度量衡的复数名词作主语时, 通常把这些名词看作一个整体, 谓语用单数, 选B或C。由第一句shall可知, 第二句陈述的是客观事实, 用一般现在时。因此选B。

10. Most of what has been said about the Smiths_______ also true of the Johnsons.　

A. are　　　　　　 B. is　　　　　　　 C. being　　　　　 D. to be　

[解析]选B。句意: 所说的关于史密斯一家的情况大部分也适合于约翰逊一家。本题缺谓语, 排除非谓语形式C、D；most of what has been said about the Smiths指代抽象事物, 用单数, 故选B。

9. At that time on the ship_______ 2, 200 people.

A. was　　　　　　　 B. is　　　　　　 C. are　　　　　　 D. were

[解析]选D。句意: 那时在船上有两千二百人。这是一个倒装句, 句子的主语是2 200 people,　 为复数, 排除A和B；at that time在那时, 为过去时时间状语, 故选D。