---We’ve seen many more days of blue skies recently. ---True. But back in 1998, ________ Beijing started its “Defending the Blue Sky” program, the city only ________ about 100 days a year.
#34101
A
which, sees
B
that, saw
C
when, saw
D
and, seeing
推荐题目
I didn’t realize my mistake ________ my teacher had a facetoface talk with me.
#32640
A
until
B
after
C
since
D
when
_______these coins are of different shapes, sizes and colors, they all date back to a long, long time ago.
#32529
A
Since
B
Unless
C
Once
D
While
---May I go and play with Tom this afternoon, mum? ---No．You can’t go out ______ your homework is being done．
#33631
A
until
B
after
C
before
D
as
My flowers grew well all the time. _________, your dog destroyed them all!
#31296
A
While
B
Although
C
However
D
And