欧美日韩黄网欧美日韩日B片|二区无码视频网站|欧美AAAA小视频|久久99爱视频播放|日本久久成人免费视频|性交黄色毛片特黄色性交毛片|91久久伊人日韩插穴|国产三级A片电影网站|亚州无码成人激情视频|国产又黄又粗又猛又爽的

The government has taken some measures to solve the shortage of electricity, but it may be some time _______ the situation improves.   

       A．since                      B．when                      C．unless                     D．before

The government has taken some measures to solve the shortage of electricity, but it may be some time ___________ the situation improves.

A. since                 B. when                C. unless               D. before

The government has taken some measures to solve the shortage of electricity, but it may be some time ____________ the situation improves.

The government has taken some measures to solve the shortage of electricity, but it may be some time _________ the situation improves.

The government has taken some measures to solve the shortage of electricity, but it may be some time _________ the situation improves.

A．since             B．when             C．before            D．unless