The government has taken some measures t
问题:
The government has taken some measures to solve the shortage of electricity, but it may be some time ________ the situation improves.[ ]
A. since
B. before
C. unless
D. when
The government has taken some measures to solve the shortage of electricity, but it may be some time ________ the situation improves.[ ]
A. since
B. before
C. unless
D. when