Question

-What a great success Shenzhou Ⅶ is!

-Yeah, our scientists must have done everything they can ________ it up．

1. A.
   send
2. B.
   sending
3. C.
   to send
4. D.
   to be sent

Answer 1

C
考查非谓语动词。everything后是省略了that及谓语动词do的定语从句，此处用不定式作状语，表目的，且send与scientists之间是主动关系，用不定式的主动形式，故选C。