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
----You haven’t said a word about the design ,Mike. What’s your idea?----I’m sorry I _______ about something else just now.
#103591
A
am thinking
B
thought
C
was thinking
D
had thought
Mr. Smith was very disappointed to see the car he had had _____ went wrong again.
#101857
A
to be repaired
B
repaired
C
it repaired
D
it
Tom with his friends ______ volleyball since three o’clock.
#103826
A
has been playing
B
is playing
C
have been playing
D
have played
Mary decided not to work on the program at home because she didn’t want her parents to know what she __________.
#101244
A
has done
B
had done
C
was doing
D
is doing