Question

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

Answer 1

D

考查連詞用法。“It be+一段時(shí)間+before…”是固定結(jié)構(gòu)，該結(jié)構(gòu)的意思是“要過……（長(zhǎng)）時(shí)間才……”。when“．．．．．．的時(shí)候”；since“從．．．．．．開始”；unless“除非”；根據(jù)題意D最佳。