We must do everything we can          waste water from running into rivers.
#48694
A
keep
B
kept
C
to keep
D
keeping
推荐题目
He enjoys ________ English in the morning.
#51351
A
read
B
to read
C
reading
D
reads
The old man was too poor ___________a room _________ . 
#48825
A
have; to live
B
to have; live
C
to have; to live
D
to have; to live in
The purpose of new inventions is _______ life more difficult, but to make it easier.
#48430
A
not make
B
not making
C
not to make
D
do not make
—We should do what we can ________ the endangered animals.—Yes, it’s our duty_________ them.
#48378
A
save; to protect
B
save; protect
C
to save; protect
D
to save; to protect
Our teacher told us          in the class.
#51008
A
don’t sleep
B
not to sleep
C
not sleep
D
not slept