—Is there any vaccine(疫苗) against H1N1 flu that can be used on humans?—No, but scientists are working to develop ________ .
#16397
A
that
B
it
C
one
D
so
推荐题目
—Do you have _______ to say today?—No, nothing.
#56935
A
something important
B
nothing important
C
important something
D
anything important
We have been looking at houses, but haven’t found ________ we like yet.
#14868
A
one
B
ones
C
them
D
it
I certainly consider _____ important that everything in the competition should be fair and open.
#14653
A
what
B
this
C
it
D
that
The tables and pictures help make ________ clear ________I wasn't sure of before.
#16777
A
it; for me to understand what
B
it; everything
C
everything; to understand what
D
/; what