Plants _________carbon dioxide and at the same time _________oxygen. So we may put some in our bedrooms to purify the air. 
#65276
A
take in, give out
B
take up, give off
C
take over, give in
D
take off, give up
推荐题目
I'd like a job which pays more, but_________ I enjoy the work I'm doing at the moment.  
#83704
A
on the other hand
B
on the contrary
C
instead
D
as a consequence
It took the scientists seven days to________Takla Makan________“the sea of death”.
#83047
A
climb;calling
B
through;called
C
across;naming
D
cross;named