Câu hỏi: China became the third country in the world to be able to independently carry __________ manned space flights.

A. by

B. up

C. on

D. out

Câu 1: He was in orbit around the Earth __________ a speed of more than 17,000 miles per hour.

A. at

B. in

C. by

D. on

Câu 2: She was very surprised ________ the grade she received.

A. at

B. on

C. of

D. about

Câu 3: He insisted ______ taking us dinner.

A. on

B. in

C. over

D. of

Câu 4: How long have they been working _____________ the company?

A. for

B. at

C. in

D. on

Câu 5: Smoking is harmful _____________ our health.

A. to

B. by

C. against

D. with

Câu 6: The pens made___________ plastic are very cheap.

A. by

B. with

C. of

D. to