I'm sorry you've been waiting so long but it'll still be some time Sundance gets back.A.

问题补充：

Im sorry youve been waiting so long, but itll still be some time Sundance gets back.

A. until

B. before

C. after

D. since

答案：

A. until

(答案→)B. before

C. after

D. since

解析：本题考查状语从句的用法。句意为:对不起让你久等了，但是还得再过一段时间Sundance才回来。故空格处须用before表示“在……之前，直到……才……”。