Our country did a lot about the drunk-driving and it took some time the situation got be

问题补充：

Our country did a lot about the drunk-driving, and it took some time the situation got better.

A. after

B. since

C. unless

D. before

答案：

A. after

B. since

C. unless

(答案→)D. before

解析：本题的含义为我们的国家做了许多有关醉酒驾驶的事，在情况变好之前花费了一些时间，before表示在……之前的含义，故本题选D。