Câu hỏi: Not until he got home he realized he had forgotten to give her the present.

A. got

B. he realized

C. her

D. the present

Câu 1: After the police had tried unsuccessfully to determine to who the car belonged, they towed it to the station.

A. the police

B. unsuccessfully

C. who

D. it to

Câu 2: Developing new technologies are time-consuming and expensive.

A. developing 

B. technologies

C. are

D. time-consuming

Câu 3: Those who had already purchased tickets were instructed to go to gate first immediately.

A. Those

B. had already purchased

C. gate first

D. immediately

Câu 4: The leader demanded from his members a serious attitude towards work, good team spirit, and that they work hard.

A. leader

B. his members

C. attitude

D. that they work hard

Câu 5: The earth is the only planet with a large number of oxygen in its atmosphere.

A. the

B. number

C. oxygen

D. its

Câu 6: The assumption that smoking has bad effects on our health have been proved.

A. that

B. effects

C. on

D. have been proved