--- did your uncle leave his hometown?
---He for nearly twenty years.
A. When; has left
B. When; has been away
C. How long; has left
D. How long; has been away
网友回答
A. When; has left
(答案→)B. When; has been away
C. How long; has left
D. How long; has been away
解析：第一空，因为后面给的动词是短暂性动词，所以用特殊疑问词when ，因为how long 与延续性动词连用，而后一个空，后接for+一段时间，所以特殊疑问词需要是延续性的，故选B