There is no doubt China has made rapid progress in space exploration.A. whetherB. thatC

问题补充：

There is no doubt China has made rapid progress in space exploration.

A. whether

B. that

C. which

D. who

答案：

A. whether

(答案→)B. that

C. which

D. who

解析：句型：There is no doubt that 毫无疑问，这也是一个同位语从句，句意：毫无疑问中国已经在太空探索中取得了快速进步。所以选B。