With the rapid development of medical science, we ________ more new drugs used in the treatment of cancer. 
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A
see
B
had seen
C
will be seeing
D
would see
推荐题目
--- Why does the lake smell terrible?--- Because large quantities of water _________.
#101273
A
have polluted
B
is being polluted
C
has been polluted
D
have been polluted
Whenever Steve sang in the shower, his voice _______ throughout the house.
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A
has rung
B
would ring
C
was ringing
D
had rung
--- Look!Somebody ___ the sofa.--- Well,it wasn’t me. I didn’t do it.
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A
is cleaning
B
was cleaning
C
has cleaned
D
had cleaned