—Jane, have you finished yourpaper?
—No, I my sister with her homework all the morning.
A. help
B. have been helping
C. helped
D. was helping
网友回答
A. help
(答案→)B. have been helping
C. helped
D. was helping
解析：考查时态。根据句意及时间状语all the morning可知，我一直在帮助，故用现在完成进行时，选B。