Câu hỏi: 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 1: 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 2: 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 3: By the time Robert will finish writing the first draft of his paper, most of the other students will have completed their final draft.

A. will finish

B. writing

C. most

D. their

Câu 4: The longer the children waited in the long queue, the more impatiently they became

A. the longer

B. waited

C. the long queue

D. impatiently

Câu 5: Some species of bats are dormant each days and active every night.

A. species of

B. each days

C. every night 

D. are dormant

Câu 6: The earth is the only planet with a large number of oxygen in its atmosphere.

A. the

B. number

C. oxygen

D. its