I won"t tell the student the answer to the math problem until he _____ on it for

题型：同步题难度：来源：

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

答案

举一反三

The little boy is dirty from head to foot because he ____ in the mud all morning.
A. has played
B. is playing
C. has been playing
D. was playing.

题型：同步题难度：| 查看答案

— Why, Jack, you look so tired!
— Well, I _____ the house and I must finish the work tomorrow. [ ]
A. was painting
B. will be painting
C. have painted
D. have been painting

题型：同步题难度：| 查看答案

Someone ____ my umbrella! It is all wet. And it was wet yesterday and the day before yesterday. [ ]
A. has used
B. has been using
C. used
D. is using

题型：同步题难度：| 查看答案

— Why are you so late? I _____ for more than an hour.
— I"m terribly sorry. I overslept and missed the bus.
A. am waiting
B. was waiting
C. have been waiting
D. will be waiting

题型：期末题难度：| 查看答案

The CCTV Spring Festival Gala Evening _____ annually since 1983.

[ ]

A. was run
B. is running
C. had been run
D. has been running

题型：模拟题难度：| 查看答案