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關(guān)閉窗口 as表示“當(dāng)……時(shí)候”時(shí)對(duì)謂語(yǔ)動(dòng)詞的限制
有這樣一道題，該選as還是when？
“I’m going to the post office.” “_________ you’re there, can you get me some stamps?”
A. As B. While C. Because D. If
【分析】此題從句意看，as 和 while 均可以填，因?yàn)樗鼈兙捎脕?lái)引導(dǎo)時(shí)間狀語(yǔ)從句，表示“當(dāng)……的時(shí)候”，于是一些同學(xué)便隨便從as、while中選擇一項(xiàng)。結(jié)果是：選as者錯(cuò)誤，選while者正確。為什么呢？因?yàn)?/FONT> as 和 while 在引導(dǎo)時(shí)間狀語(yǔ)從句表示“當(dāng)……的時(shí)候”時(shí)，有這樣一個(gè)區(qū)別：as 所引導(dǎo)的從句謂語(yǔ)通常應(yīng)是那些表示動(dòng)作或發(fā)展意義的動(dòng)詞，不能是be (是，在), have (有)，like (喜歡)，belong (屬于)等表示狀態(tài)或靜態(tài)意義的動(dòng)詞；而 while 則無(wú)此限制。所以此題的最佳答案是B而不是A。請(qǐng)?jiān)倏匆韵驴碱}，答案也選 while，不選as：
(1) _________ you are at home alone, please don’t leave the door open.
A. While B. As C. Before D. How
(2) _________ you are alone with her, tell her that you like her.
A. While B. As C. After D. How
不過(guò)順便說(shuō)一句，以上關(guān)于 as 的用法限制是針對(duì)它引導(dǎo)時(shí)間狀語(yǔ)從句時(shí)而言的，它若引導(dǎo)原因狀語(yǔ)從句，則無(wú)此限制。如：
As he is young, we can’t be too hard on him. 由于他還年輕，所以我們不能對(duì)他太苛刻。
As the wages were low, there were few applicants for the job. 因?yàn)楣べY低，沒(méi)有什么人申請(qǐng)這份工作。
The teacher told him to leave as he was a disturbance to the other students. 因?yàn)樗蓴_了其他學(xué)生，所以老師叫他出去。
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