Scientists from different countries are trying to_______ a good way to solve the energy problem.
#56513
A
keep up with
B
come up with
C
catch up with
D
meet up with
推荐题目
It’s time for supper now．Let’s__________ it．
#54658
A
stop having
B
stop to have
C
to stop to have
D
stopping to have
The girl in the classroom ______ be Maria. She called me from the library just now.
#52145
A
mustn't
B
may not
C
can't
D
needn't
In our class some students are too shy to __________ our hands when the teachers ask us to answer questions.
#59544
A
put on
B
put down
C
put out
D
put up