The question is not easy _____.
#97945
A
to answer
B
to be answered
C
answered
D
answering
推荐题目
This kind of material can be used to _____plastics.
#95998
A
taking the place of
B
take place of
C
taking place of
D
take the place of
Before he came , I’d finished _______ the whole book. 
#95608
A
to read
B
to have read
C
reading
D
read