题目内容
I won't tell the student the answer to the math problem until he ________ on it for more than an hour.
[ ]
A.has been working
B.will have worked
C.will have been working
D.isn't working
答案:A
解析:
解析:
|
“直到学生做了一个多小时,我才会告诉他数学题的答案.”根据上下文应用将来完成时,但用在时间状语从句中,应用现在时代替将来,所以用现在完成进行时. |
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