问题补充:
—Jane, have you finished yourpaper?
—No, Imy sister with her homework all the morning.
A. help
B. have been helping
C. helped
D. was helping
答案:
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。