题目内容
-Jane, have you finished your paper?
-No, I _________ my sister with her homework all the morning.
[ ]
A.
help
B.
helped
C.
have been helping
D.
was helping
答案:C
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题目内容
-Jane, have you finished your paper?
-No, I _________ my sister with her homework all the morning.
help
helped
have been helping
was helping