The world’s supplies of copper ______.(1.0)
A. have been gradually being exhausted
B. have gradually exhausted
C. are gradually exhausted
D. are being gradually exhausted
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This is the first time ______ such an accident.(1.0)
A. I see
B. I saw
C. I have ever seen
D. I had seen
The enemy ______ trouble.(1.0)
A. constantly make
B. were constantly making
C. were making constantly
D. were being made
-When is the concert supposed to start? -It ______ now.(1.0)
A. will about start
B. has about to start
C. is about to start
D. will start
By the time this talk is over, we ______ a lot about space station.(1.0)
A. shall be learning
B. are learning
C. would learn
D. shall have learnt
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