Câu hỏi: Manufacturers may use food additives for preserving, to color, or to flavor, or to fortify foods.

A. may use

B. for preserving

C. to flavor

D. to fortify

Câu 1: Passengers are required to arrive to the gate fifteen minutes before departure time.

A. are required

B. to arrive to

C. before

D. departure time

Câu 2: I can’t find the letter I received from my boss some days ago. I might throw it into the waste paper bin yesterday.

A. received

B. can’t find

C. into the

D. might throw

Câu 3: Little have people done to alleviate the sea pollution caused by the factories in central Vietnam, haven’t they?

A. have people done

B. caused

C. in central

D. haven’t they

Câu 4: Unlike the old one, this new copier can perform their functions in half the time.

A. unlike

B. can perform

C. their functions

D. in half the time

Câu 5: I think she will be suitable for the work because she has been working like a teacher for a long time.

A. will be

B. for

C. has been working 

D. like

Câu 6: Although caffeine is a moderately habit-forming drug, coffee is not regarded as harmfully to the average healthy adult.

A. moderately

B. habit-forming

C. harmfully

D. healthy