题目内容
3.Scientists say it may be five years ______ it is possible to test this mdelcine on human patients.( )A. | since | B. | until | C. | before | D. | when |
分析 科学家说这个药在病人身上试验前可能还要等5到10年.
解答 答案:C.根据选项since自从…,until直到…,before在…前,when当…时,再结合句意,在病人身上试验前可能还要等5到10年,可知此处缺少了一个引导时间状语从句的连接词,故C正确.句型It will be 段时间+before…可翻译为,还要多长时间才…
点评 本题考查时间状语从句的连接词,在充分分析句型再结合语义的基础上便能选出正确答案,同时要注意其他选项的意思

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Nightfall was approaching.Suddenly a car pulled up beside me.A man got out and offered to (38)D me.Seeing tattoos (纹身) on his arm,I became (39)C as thoughts of robberies flashed through my mind.But (40)BI could say anything,he had already begun to take the tools to change the (41)A.While watching him,I happened to look back at his car and noticed someone sitting in the passenger seat.This(42)C me.
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Finally,Jeff helped me change the tyre.I tried to offer him money and of course he refused it.As we shook hands to say goodbye I apologized for my stupid (46)C at the first sight of him,and this incident warned us that we shouldn't judge people by the way they (47)D.
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