请讲一讲结果状语从句的特点。
结果状语从句由连词 so, so that, that, such that, but (that), with the result that 和关联词 so...that, such...that 来引导。但是，在 so(主句)...that(从句)结构中，位于主句中的 so 可以省略。结果状语从句与目的状语从句的主要区别是：1. 目的状语从句一般使用情态动词，结果状语从句一般不使用情态动词；2. 结果状语从句只能放在句末；3. 结果状语从句常常用逗号与主句分开：
A. so
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He wasn't feeling well so he went to lie down on the couch. 他觉得难受,所以躺到长椅上。
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They wanted it, so they agreed to pay more than the normal price. 他们需要它，所以同意出超常的价钱。
B. so that
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One of her lungs is affected a little, so that she has to rest. 她的一个肺受了轻微感染，所以她必须休息。
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My pencil fell under my desk, so that I couldn't see it. 我的铅笔掉到书桌下面去了，所以我看不到它。
C. so... (that)
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She was so happy (that) she actually cried. 她是那么高兴,以致她真的哭了。
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That animal has so small a mouth that it can hardly eat anything. 这个动物嘴很小,以致几乎不能吃食。
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She was so angry (that) she couldn't speak. 她气得说不出话来。
D. (so)... that
I'm not a cow that you should expect me to eat grass! 我不是牛,所以你不应当指望我去吃草!
应当注意,当 so 位于句首时,主句要实行主谓语倒装(见 so ):
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So absurd was his manner that everyone stared. 他的举止那么可笑，以致大家都盯盯瞧着他。
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So terrible was the storm that whole roofs were ripped off. 暴风雨迅猛异常，以致整个屋顶都被吹掉了。
E. such... that
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It gave him such a shock that his face turned white. 这吓了他一跳,他的脸色都变白了。
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He showed such concern that people took him to be a relative. 他很关心别人,因而大家都把他当作亲人。
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The knot was fastened in such a way that it was impossible to undo. 这个结系得那么紧，根本解不开。
F. such... (that)
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It was such a boring speech (that) I fell asleep. 讲演枯燥无味, 听得我都睡着了。
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She is such a good lecturer (that) all her courses are full. 她的课讲得非常精彩,以至于她的每节课都座无虚席。
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He's such an idiot, I don't even ask him to help any more. 他是个大笨蛋，所以我甚至不再向他求助。
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It was such a lovely day we decided to go for a picnic. 天气非常好,我们决定到郊外去野餐。
与 that 相关联的、位于主句中的 such，除了用于 such a(…) + 可数名词，such(…) + 不可数名词和 such(…) + 复数名词等结构之外，还可单独使用。当 such 位于句首时，要实行主谓语倒装（即采用 CVS 语序）（见 such ）：
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Such was the force of the explosion that all the windows were broken. 爆炸力非常大，以致所有的窗户都被震碎了。
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Such was the violence of the storm that boats were sinking all around us. 暴风雨如此狂暴，以致我们周围的船只都要沉没了。