After Yang Liwei succeeded in circling the earth our astronauts desire to do is walk in s

问题补充：

After Yang Liwei succeeded in circling the earth ,our astronauts desire to do is walk in space .

A. where

B. what

C. that

D. How

答案：

A. where

(答案→)B. what

C. that

D. How

解析：“our astronauts desire to do”是主语从句，从句中缺少do的宾语