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【简答题】
_____ if he had any difficulties, he made no answer. A．Ask B．To ask C．Asked D．Asking
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【单选题】With the help of high technology, more and more new substances ______ in the past 10 years.
A.
discovered
B.
have discovered
C.
had been discovered
D.
have been discovered
【单选题】A man escaped from the prison last night. It was a long time __________ the guards discovered what had happened.
A.
before
B.
until
C.
since
D.
when
【单选题】This is an exciting area of study, and one ______ which new applications are being discovered almost daily.
A.
from
B.
by
C.
in
D.
through
【简答题】Scientists at Royal Holloway, University of London and Queen Mary, University of London have discovered that bees learn to fly the shortest possible route between flowers even if they discover the fl...
【单选题】If Newton lived today, he would be surprised by what _______ in science and technology.
A.
had discovered
B.
had been discovered
C.
has discovered
D.
has been discovered
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