第九章悬垂结构
第一节悬垂结构语法知识
所谓悬垂结构，是指现在分词( V-ing)或过去分词(V-ed)在句子中作状语时，其逻辑主语（即该动作的发出者）从文法的要求来看，必须是句子的主语，但如果该主语和现在分词或过去分词在逻辑上又没有联系，那么现在分词或过去分词就变成了一个没有依附的分词，文法上称这样的错误情况叫悬垂结构。
悬垂结构是SAT重点考查的内容。通过认识悬垂结构，可以帮助我们迅速排除一些错误选项。
例：After reading the book,一． (A)I fed the dog
(B) the dog was fed by me (C) feeding the dog was his task (D) the dog was hungry
如果reading the book作状语，作主语的成分就必须是reading the book的动作发出者。在各选项中，只有A符合条件，而其他选项的主语均不能作为reading the book的动作发出者，故正确选项为A。
当句子以V-ing开头，则句子的主语必须是该动作的发出者；当句子以V-ed 开头，则主句必须和该V-ed构成被动关系。当我们看到一个句子以V-ing或V-ed 开头时（有时前面有after、before、while或when之类的连词），首先要考虑句子主语必须和V-ing或V-ed在逻辑上有关系，凡是没有关系的必定是错误选项。
例：(A) Writing in a free style, the novelist is popular among the children (B) Written in a free style, the novel is popular among the children 在A句中，write的动作是由主语the novelist发出的，故采用V-ing形式； 在B句中，the novel是被写的，故采用V-ed形式。
为进一步了解悬垂结构，我们来分析下列例句的正误： (A) Waitine for a bus,a brick fell on my head
(B) Driving on the road that night,a squirrel suddenly leapt out of the jungle.
(C) Getting down from the bus, my ankle was sprainecL
(D) Looking out of the window, there were many people on the streets. (E) Sitting under an apple tree one night,a new idea came to Newton (F) Looking in this way,the situation didn't seem that bad (G) WritinS in a free style, the novelist is popular.
(H) Ranked as one of the top ten university, many students are eager to have the chance to study in Princeton 【分析】
(A)错。因为brick不能发出writing这样的动作。该句为典型的悬垂结构。应改为： WaitinS for a bus,1 was hit by a brick
(B)错。因为a squirrel不能发出driving这样的动作。应改为：
DrivirX; on the road that night,Tom saw a squirrel leaping out of the jungle. (c)错。发出getting down from the bus动作的是句子主语my ankle，而这从逻辑上是讲不通的。应改为：
Getting down from the bus,I got my ankle sprained
(D)错。发出looking out of the window这个动作的行为主体应是句子的主语。可改为： LookinS out of the window,Mary saw many people on the street
(E)错。是Newton发出sitting under an apple tree这个动作，故要把Newton 作为主语。可改为：
Sitting under an apple tree, Newton was hit by a new idea.
(F)错。situation是不能发出looking这一动作的，只能是被“look”，故应把looking改为looked。即：
Looked in this way,the situation didn't seem that bad (G)正确。the novelist作为主语可以发出writing这一动作。 (H)错。显然，这里是Princeton必须是主语。应改为：
Ranked as one of the top ten university, Princeton is the dream of many students who are eager to study in it.
值得注意的是，英文中有些固定的表达方式，特别是在一些表示说话人态度的
结构中，句子的主语和句首的V-ing或V-ed没有任何关系，但句子依然正确。常见的有：
a．副词+speaking
如：strictly speaking, frankly speaking, generally speaking, seriously speaking 等
等。
例：Generally speaking, women live longer than men
此句中，虽然women不是speaking的动作发出者，但由于generally speaking 为习惯表达，全句依然正确。 b．V-ing+介词
如：j uding from(从?上看)，talking of(谈到?一)，assuming( =if)，allowing for(一considering，考虑到)
例：Allowing for his age, he has done a good job. Speaking of English writing,I have an excellent tutor. Juding from his accent, he must be from Northern China. c·V-ing+从句
supposing /supposed that从句-if从句 providing /provided that从句=if从句 granting /granted that从句一although从句 allowing /considering /given that从句
例：Supposing that l would die tomorrow, what should I do today7
Assuming (if) the proposal is accepted, where can we get enough money? Given (Considering) that there was little time left,I think we should accelerate our progress.
第二节悬垂结构试题分新
1. While shopping for a birthday present for Anna, that was when Julie remembered a clearance sale at the outlet mall.
(A) that was when Julie remembered a clearance sale at the outlet mall (B) Julie remembered a clearance sale at the outlet mall
(C) then Julie's memory of the outlet mall's clearance sale took place (D) the outlet mall's clearance sale was what Julie remembered (E)a clearance sale at the outlet mall was remembered by Julie 【分析】
主语必须能发出shopping这一动作，因此只能由Julie作为主语，据此选B。
另外，A中的that不可以单独使用（除非在比较结构中）；C选项主语是Julie 的memory，不是Julie，故排除；D选项中无生命的the outlet mall的所有格不能用 ’s的形式；E采用了被动语态。 正确答案：B
2. While studying at the University of Michigan, that was when Arthur Miller developed a profound passion for writinS.
(A) that was when Arthur Miller developed a profound passion for writing (B) Arthur Miller developed a profound passion for writing
(C) then the development of Arthur Miller's profound passion for writing took place
(D) Arthur Miller's profound passion for writing was developed (E)a profound passion for drama developed in Arthur Miller 【分析】
主语必须是能发出studying这个动作的人，所以只能是Arthur Miller，只有B 符合，其它选项都应排除。
另外，A选项单独使用that;C选项违反了动词优先的原则,D选项是Mller的 profotmd passion作主语，并且使用了被动语态。 正确答案：B