Câu hỏi: _____ the children left, the house was very quiet.

A. After

B. Before

C. On

D. To

Câu 1: We were very grateful _________ our friends for all of their assistance.

A. to

B. for

C. off

D. with

Câu 2: His opinion is different _____________ mine.

A. to

B. with

C. about

D. from

Câu 3: If there was a technical failure, Gagarin might never get __________ to the Earth.

A. to

B. back

C. from

D. down

Câu 4: If you don’t pay attention_________ the teacher, you won’t understand the lesson.

A. for

B. to

C. at

D. about

Câu 5: We areall aware____________ the importance of the environment protection.

A. of

B. about

C. to

D. of

Câu 6: He had learned the whole poem _____ heart.

A. in

B. of

C. to

D. by