问题补充:
—Has William finished writing his graduation paper yet?
—I don’t know exactly,but he all day.
A. is writing
B. has been writing
C. was writing
D. wrote
答案:
A. is writing
(答案→)B. has been writing
C. was writing
D. wrote
解析:表示“一整天都在做某事(此时该动作还没有结束)”要用现在完成进行时。