问题补充：
--Why has he been staying at home these days?
--He since a month ago.
A. has been out of work
B. was out of work
C. has lost his work
D. had left from his work
答案：
(答案→)A. has been out of work
B. was out of work
C. has lost his work
D. had left from his work
解析：答语中有since引导的时间状语，限定了句中的动词为持续性动词。
