The two friends on the Internet for three hours and they would go on till the next mornin

问题补充：

The two friends on the Internet for three hours, and they would go on till the next morning.

A. have been chatting

B. had been chatting

C. were chatting

D. had chatted

答案：

(答案→)A. have been chatting

B. had been chatting

C. were chatting

D. had chatted

解析：考察时态。根据后面的for three hours可知是与完成时连用。B项是过去完成时，应该有明显的时间状语，本题没有。根据句意可知A正确。句意：那两个朋友一直在网上聊了3个小时。