---Hasourgovernmenttakensomemeasurestoovercomethelacko...

问题详情：

 --- Has our government taken some measures to overcome the lack of electricity?

--- Yes, but it may take some time ________ we have enough power.

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

【回答】

 D

知识点：连词

题型：选择题