名师点睛

Q1：满胜老师好，我想问一下“There were many delicious dishes， all cooked exactly as he liked them.”这个句子中的as从句怎么解读。它是方式状语从句吗？这个them为啥感觉怪怪的？

A1：这个as从句是方式状语从句，修饰cooked，用来表示烹饪的方式。我们可以把as改为the way说成the way he liked them，这里的them指代dishes。因为方式状语从句的基本结构是“as +完整的陈述句”，比如这里he liked them就是一个完整的陈述句，所以句末的them保留了。再比如：a. I don't understand why he behaves as he does. （我不理解为什么他要那样做。） b. I was never allowed to do things the way I wanted to do them. （我以前從来都不被允许按照自己的意愿来做事。）可以看到，在这两句话中as、the way后边接的都是完整的陈述句。

方式状语从句除了可以单纯地谈论某个动作的方式（如以上例句）外，还可以比较两个动作的方式。比如：John wore his hat perched on the back of his head， just as his favorite old movie stars did. （约翰把帽子扣在脑后，就如同他喜欢的那些老电影明星戴帽子的方式一样。）句中的just是为了强调，所以我们经常会见到just as引导的方式状语从句。这样的as从句还可以用在be动词后边。比如：Your sentence is exactly as I would have said it.

最后值得注意的是，题干句子中的“all cooked ...”是一个独立分词结构，其中cooked是过去分词，all是cooked的逻辑主语，相当于all （dishes） were cooked ...。

Q2：请教满胜老师，下面这两个as从句到底该如何分析它们的逻辑结构，我一点头绪都没有。如何区分as引导的到底是定语从句还是状语从句？从句的意思怎么翻译比较准确？

a. Cattle were introduced from Asia， as probably were domestic sheep and goats.

b. Wind velocity increases with latitude and may cause serious stress for trees， as is made evident by the deformed shapes at high altitudes.

A2：虽然两个as从句都含有as be结构（分别是as were和as is），但二者有本质差别。a句中的as从句结构是“as +助动词+主语”，而b句的as从句结构是“as （主语） +谓语”。也就是说，a句的as从句是一个倒装句，as代指前面句子所说的情况，而b句的as从句是一个定语从句，as直接充当从句的主语。下面我来举例详述。

“as +助动词+主语”是描述一个与前面主句的谓语情形相同的情形（used to add that what you have said is also true of someone or something else）。或者说，这里的as代替了前面主句的谓语内容。比如：John is tall， as is his father. （约翰很高，他爸爸也很高。）这里的as is相当于is tall。再比如：I love English， as does John. （我喜欢英文，约翰也是。）这里的as does相当于loves English。

据此分析，我们来看a句：Cattle were introduced from Asia， as probably were domestic sheep and goats. 后半句话就相当于domestic sheep and goats were also introduced from Asia，整句话的意思是“牛是从亚洲引进的，家畜绵羊和山羊很可能也是（从亚洲引进的）”。再比如：Interestingly， the Chinese associate "green" with "unripe"， as do we English speakers. 句中的as do替代了前面主句的谓语associate "green" with "unripe"，整句话的意思是“有趣的是，中国人把‘绿色的和‘未成熟的联系在一起，这就如同我们这些讲英语的人一样”。

那么，这样的as从句算是什么从句呢？考虑到它其实是一个完整的句子，因此应该是状语从句，而不是定语从句。我们可以把它看成是一个含有比较意味的方式状语从句，但这里的比较与问题一中所说的比较动作方式不同，此处是比较整个谓语内容。请比较下面两个句子：c. Mary cooked a turkey as Jenny did. d. Mary cooked a turkey， as did Jenny. c句通常被理解成是在比较Mary和Jenny烹饪火鸡的方式，尤其是当把did换成表示虚拟的would have时（Mary cooked a turkey as Jenny would have.）就更会这么理解了。而d句则是表示两人都烹饪了各自的火鸡，而不表示比较烹饪方式。

综上所述，as方式状语从句可以有三个层面的含义和用法：一是单纯谈论某个动作的方式，比如：There were many delicious dishes， all cooked exactly as he liked them （as从句表示烹饪的方式）. 二是比较两个动作的方式，比如：In spite of our warnings and explanations it drew him as the moon draws water （the moon draws water是完整的陈述句）. 三是比较两个谓语内容，说它们是一样的，此时采用倒装句结构“as +助动词+主语”，比如：It can be quite an eye opener to see the range of classical apples still in existence， such as Decio which was grown by the Romans. Although it doesn't taste of anything special， it's still worth a try， as is the knobbly （多疙瘩的） Cat's Head （as从句相当于the knobbly Cat's Head is also worth a try，即Decio和Cat's Head两种苹果都值得尝尝） which is more of a curiosity than anything else.

接下来我们来讨论问题中的b句：Wind velocity increases with altitude and may cause serious stress for trees， as is made evident by the deformed shapes at high altitudes. 这是as引导的非限制性定语从句，as指代前面主句的内容，整句话的意思是“风速随着海拔的升高而增大，并且可能导致树木面临巨大的应力，这一点从高海拔地区树枝的扭曲变形可得到证实”。这里的as在定语从句中充当主语，后接谓语is made，形容词evident是主语补足语。我们也可以引入动词evidence，把as is made evident替换成as is evidenced：Wind velocity increases with altitude and may cause serious stress for trees， as is evidenced by the deformed shapes at high altitudes. 大家可以把“as is evidenced by ...”当成一个句型来记，基本意思是“这一点被……所证实”。比如：The volcano is still active， as is evidenced by the recent eruption. （这座火山还是座活火山，这一点已经被最近一次的喷发证实。）再比如：In addition to scientific talent， John had artistic talent， as is evidenced by the excellent drawings in his papers about the nervous system. （除了科学才能，约翰还有艺术方面的才华，这一点从他那有关神经系统的论文中的精美绘画可得到证实。）

延伸拓展

在英文中，as可以引導各种逻辑结构的从句，这是一个难点。上文我们讨论了as引导的方式状语从句和定语从句，关于二者的区分，最简单的判断就是：as引导的方式状语从句是完整的，而as引导的定语从句是不完整的，因为as要在定语从句中充当句子成分（比如主语或宾语）。只不过，as引导的方式状语从句有时会采用省略结构，这就让句子结构看起来不完整，因而会被误判为定语从句，最终导致逻辑语义关系理解错误。所以，大家还是要熟练掌握各类as从句的逻辑构造原理，方能真正驾驭as从句。