1、将下列句子变成被动语态：[主要步骤是：把原句的宾语变成主语（代词宾格要变成主格）；把原句的谓语动词变成被动形式（注意：时态不变，新谓语动词与新主语要一致，疑问句要注意助动词的转换）。复合句中如有可能主句和从句都要变成被动语态。]
1）He gave me a present.
I was given a present by him.
2）My sister made the soup.
The soup was made by my sister.
3）The workers could not find the manager anywhere in the factory.
The manager could not be found anywhere in the factory by the workers.
4）The army engineers and soldiers have built a bridge over the river.
A bridge has been built over the river by the army engineers and soldiers.
5）The police will surely arrest the thieves.
The thieves will surely be arrested by the police.
6）My brother will repair my bike for me.
My bike will be repaired by my brother.
7）You must clean your watch once a year.
Your watch must be cleaned once a year.
8）I didn’t tell you Xiao Wang could do the job.
You were not told (that) the job could be done by Xiao Wang.
9）I cannot find my dictionary. Someone has taken it.
My dictionary cannot be found. It has been taken by someone.
10）She cannot find her bag. Someone must have taken it.
Her bag cannot be found. It must have been taken by someone.
11）The pupils asked the teacher to tell a story.
The teacher was asked by the pupils to tell a story.
12）The Association asked Mr. Green to make a speech. Mr. Green was asked by the Association to make a speech. 13）The government is sending him abroad.
He is being sent abroad by the government.
14）He told me to wait here for him.
I was told to wait here for him.
15）Mr. Hopkins has found his wallet.
Mr. Hopkin s’ wallet has been found.
16）The workers themselves invented the new machine. The new machine was invented by the workers themselves. 17）They set up this hospital in 1950.
This hospital was set up in 1950.
18）Tom broke the window.
The window was broken by Tom.
19）Did you write the letter?
Was the letter written by you?
20）They do not make this kind of watches in Beijing.
This kind of watches are not made in Beijing.