问题补充:
I don’t know.
Because he has to look after his mother.
A. why he is leaving
B. why is he leaving
C. whether he is leaving
D. whether is he leaving
答案:
(答案→)A. why he is leaving
B. why is he leaving
C. whether he is leaving
D. whether is he leaving
解析:英语宾语从句中一般用陈述语序。根据下文,因为他必须照顾她的母亲。可知上文提问的是原因,选项B为倒装语序,故选A,我不知道他为什么离开了。