Chuyển những câu sau thành câu bị động:
1) Many people learn Chinese nowadays.
2) They grow a lot of rice in tropical countries.
3) I took my younger sister to the park last Sunday.
4) Nobody can do such a thing.
5) They are building a new supermarket here.
6) Mu mother told us to be here at 6 o'clock.
7) We must solve the problem before we leave.
8) When did they last paint th house ?
9) Columbus discovered America more than 400 years ago.
10) They publish many books every year.
11) Careless driving causes many accidents each year.
12) They didn't give me the information I needed.
13) Has anybody told you what to do?
14) You ought to do it as soon as possible.
15) When did Alexander Graham Bell invent the telephone?