— ____ sweep the classroom yesterday？—I was playing tennis with my friend．
#104570
A
Why not
B
Why didn't
C
Why don't
D
Why didn't you
推荐题目
It took me a long time before I was able to fully appreciate what they ______ for me.
#102297
A
had done
B
did
C
would do
D
were doing
---Do you know when she _________?---Sorry, I don’t. But I’ll let you know when she _________.
#100647
A
comes, comes
B
comes, will come
C
will come, will come
D
will come, comes
The best way to prevent the air polluting _____ , but the sky is still not clear.
#102116
A
is used
B
are used
C
has been used
D
have been used
Social attention should be paid our earth from .
#102039
A
to prevent; being polluted
B
to preventing; polluted
C
to prevent; polluting
D
to preventing; being polluted