______ I admit that there are problems, I don't agree that they cannot be solved.
#30120
A
As
B
If
C
While
D
When
推荐题目
 Mr. Green has made another wonderful discovery,  ______ great importance to science.
#34201
A
which I think is of
B
which I think it is of
C
that I think is of
D
I think which is of