You shouldn’t have the machines ______ all the while. You ought to have them ______ now and then.
#97579
A
run; repair
B
running; repairing
C
run; repaired
D
running; repaired
推荐题目
Having arrived at the station, _____. 
#98250
A
it was found that the train had left
B
the train had left
C
the train was found left
D
he found that the train had left
—I would like to buy an expensive camera.—Well.We have several models________.
#88718
A
to choose from
B
of choice
C
to be chosen
D
for choosing
Our headmaster suggested    a discussion on the subject.
#96383
A
making
B
having
C
to have
D
to make