中国石油大学 / 中石油
正确率:100%
28.(2.0分) 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、had worked
A、has been working
B、will have worked
C、will have been working
D、had worked
参考答案:
佳题速递: