1/ Mary asked me if I went to Lan's house the day before/ the previous day.
2/ The glass was broken into small pieces.
4/ Lan said that she was thirsty and she wanted some milk.
6. .It is easy to keep silent in class.
7/ It is not easy to rake care of children.
8/ Nam said "How many books do you have,Ba?"
Nam said how many book i had .
16/ "I'm very pleased to see the ricecooking contest" Lisa said.
lisa said i was very pleased to see the ricecooking contest

3/ Can you stop smoking, please?
Would you mind stopping/ not smoking, please?
5/ May I go home early?
Do you mind if I go home early?
C2: would you mind if I went home early?
8/ Nam said "How many books do you have,Ba?"
Nam asked Ba how many books Ba had. 
9/ They like going out inthe evening.
They enjoy going out in the evening.
10/ People must speak English in the English club.
English must be soken in the English club.
11/ He makes his parents happy because he passes the exam.
Because of passing the exam, he makes his parents happy.
12/ It is safe to go out with some friends in the evening.
Going out with some friends in the evening is safe.
13/ They boy is Ba. He is talking to Nga.
They boy who is talking to Nga, is Ba
C2: The boy talking to Nga, is Ba. 
14/ These toy cars are expensive. They are made in China.
These toy cars which are made in China, are expensive.
C2: These toy cars made in China, are expensive.
15/ Milions of tourrist visit the Taj Mahaj in India every year.
The Taj Mahaj in India is visited by millions of tourist every year. 
16/ "I'm very pleased to see the ricecooking contest" Lisa said.\
Lisa said that she was very pleased to see the rice cooking contest.
17/ You are in the theater and you want to take a seat. You say to the other person:
Do you mind ì I sit here? (câu này bạn tham khảo nha vì không chắc lắm)
18/ Jack is learning English. He want to study abroad.
Jack is learning English in order to study abroad. 

Nga did the housework yesterday The housework