—How was that? —I was chatting on line the power went out.A. becauseB. whileC. asD. when

问题补充：

—How was that?

—I was chatting on line the power went out.

A. because

B. while

C. as

D. when

答案：

A. because

B. while

C. as

(答案→)D. when

解析：考查连词：A. because因为，B. while当…时候，虽然，然而，C. as随着，因为，正如，D. when当…时候，句意：怎么了？--我正在聊天这时停电了。When引导时间状语，表示时间点，这里翻译成“这时”，while引导时间状语从句，表示“一段时间”，as引导时间状语从句，表示“两个动作同时发生”，选D。