I think ______ is necessary ______ us to do something useful to protect the birds.
#50276
A
this; for
B
it; of
C
this; of
D
it;for
推荐题目
-----______ are the students talking ______? ----- A policeman.
#49207
A
What, with
B
Who, for
C
Who, to
D
What, to
He entered Peking University____. The people in his village are ____ him. 
#46195
A
in the end; pride in
B
at the end; pride of
C
in end; proud of
D
in the end; proud of
–Where is the library? -- It’s_____ a classroom.
#49127
A
in the front of
B
in front of
C
in
D
between