Câu hỏi: Jason’s professor had him to rewrite his thesis many times before allowing him to hand it in.

A. had

B. to rewrite

C. many times

D. allowing

Câu 1: It has ever been told that teaching is one of the more noble careers.

A. has ever been

B. is

C. the 

D. more noble

Câu 2: The mother asked her son if he would have the floor clean the day before.

A. asked

B. if

C. would have

D. clean

Câu 3: Ecologists are trying to preserve our environment for future generations by protecting the ozone layer, purifying the air, and have planted the trees that have been cut down.

A. to preserve

B. for

C. the ozone layer

D. have planted

Câu 4: When a patient's blood pressure is much higher than it should be, a doctor usually insists that he will not smoke.

A. much

B. than it

C. should be

D. will not

Câu 5: Before went abroad, he had finished his English course at the English-speaking Center.

A. went

B. abroad

C. had finished

D. English-speaking

Câu 6: Abraham Lincoln was a good president and was self-educated, hard working and always told the truth.

A. a good president

B. self-educated

C. hard working

D. always told the truth