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1、before句型辨析与解析 before句型辨析与解析 It + will be + 时间段 + before等表示“在之后才”的句型总结 一、用于句型“It + will be + 时间段 + before.”句型中,表示“要过多久才”,也可用于“It + may be + 时间段 + before.”,表示“也许要过多久才”。Before 后的句子中用一般现在时态。 其否定形式“It will/would not be +时间段+ before”表示“不久就,过不了多久就”。 The field research will take Joan and Paul about five mon
2、ths; it will be a long time _ we meet them again. A. after B. before C. since D. when How long do you think it will be _China sends a manned spaceship to the moon? Perhaps two or three years. A. when B. until C. that D. before It _ long before we _ the result of the experiment. A. will not be.will k
3、now B. is.will know C. will not be.know D. is.know (4) Scientists say it may be five or six years_ it is possible to test this medicine on human patients. A. since B. after C. before D. when 解析:答案为BDCC。考题 (2)before 用于肯定的“It + will be + 时间段 + before.”句型中,表示“要过多久才”。 before在本题中用于否定句,意为“过不了多久就会”, 状语从句要用
4、一般现在时代替一般将来时,可知C项为正确答案,句意是:要不了多久我们就会知道试验的结果了。 宾语从句中含有句型“It + may be + 时间段 + before.”,表示“也许要过多久才”,故选择答案C。 二、用于句型 “it was +时间段+ before ” 表示 “过了才”。其否定形式“ it was not +时间段+ before ” 意为“不久就”, “没过就”。 It was some time _we realized the truth. A. when B. until C. since D. before 解析:答案为D。before用于句型“it was +时间段
5、+ before ” 表示 “过了才”。该题题意是“过了一段时间我们才意识到事情的真相”。故正确答案为C项。 表示“在之后才”。副词“才”在汉语中强调某事发生得晚或慢。如果在含有before从句的复合句中,强调从句动作发生得晚或慢时,就可以应用这种译法。 The American Civil War lasted four years _ the North won in the end. A. after B. before C. when D. then 解析:答案为B。本题考查连词before表示“在之后才”之的用法,根据本句含义“美国南北战争持续了四年,北方才最终取得胜利”,可知本题应
6、选B。 三、表示“还没来得及就”。目的在于强调从句动作发生之前,主句动作已发生。 Why didnt you tell him about the meeting? He rushed out of the room _ I could say a word. A. before B. until C. when D. after 解析:答案为A。本题考查连词before表示“还没来得及就”的用法。句意是“我还没来得及说一句话,他就冲出了房间”。 四、表示“在之前就”。这时主句与before从句中的两个动作按时间先后依次发生。 It was evening_ we reached the li
7、ttle town of Winchester. A. that B. until C. since D. before 解析:答案为D。本题考查连词before表示“在之前就”的用法。句意是“我们到达小镇Winchester之前就已经是傍晚时分了”。 五、表示“趁”,“等到”,或 “没等就 ”等。 He made a mistake, but then he corrected the situation _ it got worse. A. until B. when C. before D. as 解析:答案为C。由made a mistake和转折词but可知本题句意是“他出了差错,
8、但没等其进一步恶化,他就调整了局势”。故正确答案为C项。 六、和hardly,scarcely连用,表示“刚一就”。该结构主句常用过去完成时,当hardly位于句首时,要用倒装语序,例如: I had hardly sat down before the telephone rang.=Hardly had I sat down before the telephone rang. 我刚一坐下电话就响了。 We had scarcely reached the school before it began to rain.= Scarcely had we reached the school
9、 before it began to rain我们刚到学校天就下雨了。 七、和其它相似句型的区别 有时候before引导的时间状语从句与since,when引导的时间状语从句在下列结构中较相似,容易混淆。 “It be +时间段 + since引导的时间状语从句”表示“自从已经有多长时间了”。主句用一般现在时或现在完成时。 “It be +时间点 +when引导的时间状语从句”表示“某个动作发生时,是某个时间”。主句谓语动词可以是一般过去时,也可以是一般将来时。 It is almost five years _we saw each other last time. A. before B
10、. since C. after D. when Did Jack come back early last night? Yes. It was not yet eight o clock_ he arrived home. A. before B. when C. that D. until 解析:答案为BB。考题考查的是“It be +时间段 + since引导的时间状语从句”结构,句意是“自从上次我们见面以来已经近五年没有见了”,故选择答案B。考题考查的是句型“It be +时间点 +when引导的时间状语从句”,句意是“他昨晚回家时还不到8点”,故选择答案B。 八、before lo
11、ng和long before的区别 before long意为“不久,很快”,常在句中作状语,多与动词的过去时或将来时连用。例如: The work will be finished before long. 工作不久就会完成。 Before long he had to move on again. 不久,他被迫再次迁移。 long before意为“很久以前”这个词组常与过去时或过去完成时连用,跟从句时也可用在一般现在时的句子中。例如: She said that she had heard of it long before. 她说她早就听说过此事。 It will be long before he arrives. 还要等很久他才能到达。