China's success in manned－spacecraft travel shows our country has become one of the great

问题补充：

Chinas success in manned－spacecraft travel shows our country has become one of the greatest powers in space research.

A. what

B. which

C. /

D. it that

答案：

A. what

B. which

(答案→)C. /

D. it that

解析：该句中的从句作shows的宾语，是宾语从句，又因为从句中不缺主、宾语，所以只能用that引导；又因引导宾语从句时that可以省略，所以答案是C。