Câu hỏi: Most of the houses on the street was built in the previous century.

A. of

B. on

C. previous

D. was

Câu 1: It is important that you turned off the heater every morning before you leave for class.

A. turned off

B. before

C. important

D. leave for

Câu 2: Unlike many writings of her time, she was not preoccupied with morality.

A. writings

B. of her time

C. preoccupied

D. with morality

Câu 3: Both Mr. and Mrs. Smith are explaining the children the rules of the game.

A. Both Mr. and Mrs. Smith

B. are

C. explaining

D. the children the rules of the game

Câu 4: She did not know where most of the people in the conference was from.

A. did not

B. where

C. the

D. was

Câu 5: Hardly did he enter the room when all the lights went out.

A. did he enter

B. when

C. the lights

D. went

Câu 6: Oxygen plays a important role in maintaining live.

A. a

B. plays

C. role

D. live