(2013·重庆模拟)—When did your brother begin to show his interest in medicine? —It was a Saturday he noticed his classmate experimenting on a frog in the lab.
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推荐题目
After living in Paris for fifty years，he returned to the small town he was raised．
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which
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that
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when
I often watch CCTV-9, ________ I have learned a lot of new words and expressions.
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from which
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of which
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to which
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which