New technology ______ to make sure that the cars, taxis, buses and trains we use ______ the air.
#104707
A
is used; not to pollute
B
has used; is not polluted
C
is being used; do not pollute
D
has been used; to pollute
推荐题目
By the time you get to Shanghai tomorrow, I_____ for Chongqing.
#102322
A
would have left
B
have left
C
shall have leaving
D
will have left
—Did you happen to hear the recent news? —Yes, Alice ____ the gold medal in the speech contest, which I find hard to believe．
#101840
A
wins
B
won
C
had won
D
will win
It is the first time that I ______ this kind of moon cake.
#101741
A
enjoyed
B
have enjoyed
C
had enjoyed
D
enjoy
If nothing ________, the oceans will turn into fish deserts.
#100592
A
does
B
had been done
C
will do
D
is done