Câu hỏi: By measuring the color of a star, astronomers can tell how hot is it.

A. measuring

B. the

C. how

D. is it

Câu 1: 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 2: The bus was plenty of people who had spent many a happy hour shopping at the new.

A. plenty of

B. who

C. many a happy hour

D. shopping

Câu 3: When a lion gets hungry, its manner changes and it becomes threatened.

A. when

B. its manner 

C. and

D. threatened

Câu 4: Not everyone realizes that the most largest organ of the human body is the skin.

A. not everyone

B. most largest

C. human

D. is

Câu 5: Sometimes it takes me about three hours finishing my round.

A. sometimes

B. me

C. hours

D. finishing

Câu 6: 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