He has a hard time          the problem.
#42186
A
works out
B
working out
C
work out
D
works out
推荐题目
---What do you usually do when it is raining?---I often ______ TV. 
#39810
A
are watching
B
watch
C
watches
D
watching
The computer is broken. ___it___ today?
#42253
A
Will; repair
B
Has; repaired
C
Will; be repaired
D
Has; been repaired