Pollution is a serious problem. Scientists have _______ some good ways to save it.
#55161
A
come up with
B
come on
C
come out
D
come up
推荐题目
Hurry up, Mike. You must get to the airport an hour before the plane________.
#58726
A
gets off
B
turns off
C
puts off
D
takes off
--- What __________ he do? --- He __________ an actor.
#61927
A
is, is
B
does, does
C
does, is
D
is, does
Mr. Black asks the kids ________ in the river, because it’s too dangerous.
#55054
A
swim
B
to swim
C
not to swim
D
swims
Although Maths is very difficult, you can’t .
#55387
A
give in it
B
give it in
C
give up it
D
give it up
---How long have you ________ your penfriend?---For five days. I received it last Sunday.
#55002
A
heard from
B
received the letter from
C
heard of
D
had the letter from