Did Jack come back early last night?Yes. It was not yet eight o’clock he arrived

问题补充：

--- Did Jack come back early last night?

--- Yes. It was not yet eight o’clock he arrived home.

A. before

B. until

C. when

D. af ter

答案：

A. before

B. until

(答案→)C. when

D. af ter

解析：考察时间状语从句。句意：—Jack昨天晚上回来的早吗？—是的，当他回来的时候还没有到8点。本句中的when he arrived home.是一个时间状语从句。本题容易错选A项，但是ABD三项与句意不符。