-- What can trees do _________ us ?--- They can _________ harmful gases and produce oxygen .
#58609
A
helping , take in
B
to help , take in
C
helping , take out
D
to help , take care
推荐题目
Boys_________ model planes to dolls, while girls _________ have dolls than model planes.
#52349
A
would rather; prefer
B
prefer; would rather
C
would rather; would rather
D
prefer; prefer
Jack ______ be in the library. He is playing football on the playground.
#54032
A
can’t
B
can
C
need
D
must not学科
－Excuse me, does Mr Smith’s son live here?－He _________ be here, but he has moved.
#60880
A
has to
B
used to
C
tried to
D
happened to
It’s difficult _____ your sound because the noise is too high.
#61203
A
to listen
B
to know
C
to learn
D
to hear