This is 3-D printer. And this is an artificial (人工的) ear. Can you believe that scientists printed this artificial ear by this 3-D printer?
#33175
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a
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an
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the
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推荐题目
－This is a useful dictionary, I think.－So it is, and it’s ______ unusual one.
#33289
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the
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an
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a
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不填
There is ________ useful book on the desk， _________ useful book belongs to my brother．
#32811
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a; the
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an; the
C
a; an
D
an; a
--I want to write __________ article about the great inventors in the world. Can you help me? --Sorry, I don’t know much about __________ topic.
#32465
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an; a
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an; the
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the; a
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the; the