问题
选择题
-- _____________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
答案
答案：B
根据答语内容可知问的内容可知答案为B，for +一段时间，用have been aways，表示，故选B