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
--- The accident might not have happened , had we been more careful . --- But we _______.
#103641
A
didn’t
B
hadn’t
C
weren’t
D
don’t
I first met John at my sister’s wedding. He ____ with the bridegroom at the time.
#100985
A
talked
B
had talked
C
had been talking
D
was talking
Principal White has been working in the school for about 20 years, all his energy to teaching and researching as well as the running of a healthy school．
#102248
A
devoted
B
devoting
C
to devote
D
and devote
—Look! Somebody ______the blackboard．—Well, it wasn't me．I didn't do it．
#101314
A
is cleaning
B
was cleaning
C
had cleaned
D
has cleaned
—Tommy is planning to buy a car.—I know. By next month he _____ enough for a used one.
#100921
A
will have saved
B
saved
C
will save
D
saves