1. He gave me a present.
_______________________________________________________
答案：I was given a present by him.
2. Workers can't find the manager.
_______________________________________________________
答案：The manager can't be found by workers.
3. The villagers have built a bridge over the river.
_______________________________________________________
答案：A bridge has been built by the villagers.
4. The police will surely arrest the thief.
_______________________________________________________
答案：The thief will surely be arrested.
5. The farmer was ploughing the field.
_______________________________________________________
答案：The field was being ploughed by the farmer.
6. Have they paid you the money?
_______________________________________________________
答案：Have you been paid the money by them?
7. Mr. Wang gave us an English lesson.
_______________________________________________________
答案：We were given an English lesson by Mr. Wang.或：An English lesson was given to us by Mr. Wang.
