He has a hard time          the problem.
#42186
A
works out
B
working out
C
work out
D
works out
推荐题目
There __________heavy rain tomorrow. 
#39297
A
is
B
have
C
will be
D
will have
_____ the girl _____ her hands now?
#41963
A
Does; wash
B
Is; wash
C
Is; washing
D
Do; wash