The government has taken some measures to reconstruct the earthquake-hit areas but it mus

问题补充：

The government has taken some measures to reconstruct the earthquake-hit areas, but it must be some time everything returns to normal.

A. since

B. after

C. unless

D. before

答案：

A. since

B. after

C. unless

(答案→)D. before

解析：考查固定结构。It+be +some time+before….要过一段时间才。。。。句意：政府已经采取措施重建地震灾区，但是必须要过一段时间一切才能恢复正常。选D。