—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
The number 5.12 is a special number, ______I think, that will be remembered by the Chinese forever.
#16234
A
what
B
it
C
which
D
one
The Smiths have three daughters, one a baby, and ________ twins of twelve.
#16798
A
another
B
the other
C
others
D
the others