省略連詞if 采用倒裝的非真實條件句
　　在書面語中，條件從句可以不用連詞if, 而將謂語中的過去式were,had或should等移至主語之前，構成倒裝。
　　例：Were you in my position, you would do the same.
　　假如你處在我的地位，你也會這樣干的。
　　例：Had he come earlier, he would have met her.
　　要是他早點來的話，他就會見到她了。
　　虛擬語氣在儲蓄條件句中的應用
　　非真實條件句中的條件從句有時不表示出來，只暗含在短語或上下文中，這種句子叫做儲蓄條件句。常見的有but,for ,without等引導的短語，以及or, or else, otherwise, but 等后面的分句。
　　例：But for your help we couldn’t have succeeded in the experiment.
　　如果沒有你的幫助，我們的實驗室是不會成功的。
　　例：We could have done better under more favourable conditions.
　　在更有利的條件下，我們能夠做得更好些。
　　經典考點：
　　1、____right now, she would get there on Sunday.
　　A)Would she leave
　　B)If she leaves
　　C)Were she to leave
　　D)If she had left
　　2、____for my illness I would have lent him a helping hand.
　　A)Not being
　　B)Had it not been
　　C)Without being
　　D)Not having been
　　3、We didn’t know his telephone number, otherwise we ____him.
　　A)would have telephoned
　　B)must have telephoned
　　C)would telephone
　　D)had telephoned
　　4、A safety analysis____the target as a potential dandger Unfortunately, it was never done.
　　A)would identify
　　B)will identify
　　C)would have identified
　　D)will have identified
　　解析：
　　1、答案選C。從句子結構可知，本題是表示與將來事實相反的虛擬語氣。主句的謂語是“should+動詞原形”。同時，從句省略了連詞if, 可以將were提前，構成倒裝。只以C符合語法規(guī)則。本題意思：如果她馬上動身的話，她可能在星期天到達那里。
　　2、選B。從句子結構可知，空缺處應填入表示與過去事實相反的虛擬條件從句，并且將連詞if 省略。此時應把虛擬語氣的謂語動詞提前。符合語法規(guī)則的只有B項。
　　3、選A。本題中otherwise引出的是一種與事實相反的假設條件，后面的句子應用虛擬語氣。前一分句暗示了一個過去的時間，所以用不著would have done的形式，相當于If we had known his telephone number, we would have telephoned him.
　　4、選C。根據unfortunately后面直接陳述一個過去的事實，可以推斷出第一個句子里含有一種“應該做某事而沒有做的”虛擬條件。C項用于表示與過去事實相反的虛擬語氣，正合題意。B、D不是虛擬語氣。

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