说明：
本文是在国内GMAT考生中广为流传的PREP语法笔记整理而成。这些PREP题目，包括了老PREP和新PREP中的各2套共493道题目。我们把这些题目，按20道题目一组，创建了25个练习册，方便大家先做后看。
注意：此部分解析为非官方、非专业老师整理的解析。
211. (GWD-8-Q39，OG12-136)
Whereas in mammals the tiny tubes that convey nutrients to bone cells are arrayed in parallel lines, in birds the tubes form a random pattern.
A. Whereas in mammals the tiny tubes that convey nutrients to bone cells are arrayed in parallel lines, in birds the tubes
B. Whereas the tiny tubes for the conveying of nutrients to bone cells are arrayed in mammals in parallel lines, birds have tubes that
C. Unlike mammals, where the tiny tubes for conveying nutrients to bone cells are arrayed in parallel lines, birds’ tubes
D. Unlike mammals, in whom the tiny tubes that convey nutrients to bone cells are arrayed in parallel lines, the tubes in birds
E. Unlike the tiny tubes that convey nutrients to bone cells, which in mammals are arrayed in parallel lines, in birds the tubes
题目释义：Whereas in mammals…., in birds…
考点：
比较（comparison）
1. 比较：
(1) whereas = while（while前后句子之结构要求并列相对）
(2) whereas连接的平行比较只要求对比的核心逻辑上有对称关系，不要求对称位置必须是对称名词，下面句子中主从句的主语分别是energy和nuclear power并不是对称名词，但是对比的核心都是“核能发电占总产出能量的份额”：
如OG12-131 Over 75 percent of the energy produced in France derives from nuclear power, whereas nuclear power accounts for just over 33 percent of the energy produced in Germany.
*：但是如果whereas后面接介词短语，那么主句的开头也必须需要是介词短语(whereas后出现介词短语或者状语都会非常对称)，如果whereas后接单纯主谓宾（或主系表），主句也要尽量用单纯的主谓宾（或主系表）来对应，除非同下面GWD 18-2一样后半句主谓即已经可完全表达出“对称”的含义（each language occupies a distinct area of the brain是主谓宾齐全；language areas overlap是主谓，没有宾语。但两个分句依然算是平行，因为逻辑已经平行。）：
prep1-29 Pine trees thrive in relatively wet climates, whereas oaks prefer drier ones.
prep1-54 In cooking, small quantities of spices are used, whereas in medicinal usage spices are taken in large quantities in order to treat particular maladies.
prep2-102 Whereas a female grizzly bear in the Rockies typically occupies a range of 50 to 300 square miles, a male will cover 200 to 500 and occasionally as many as 600.
prep1-194. Whereas the honeybee’s stinger is heavily barbed and cannot be retracted from the skin, the yellow jacket’s stinger is comparatively smooth, and can therefore be pulled out and used again.
大全933. Whereas owners of condominium apartments have free and clear title to their dwellings, owners of cooperative apartments have shares in a corporation that owns a building and leases apartments to them.
GWD18-2 According to findings derived from functional magnetic resonance imaging (MRI), the area of the brain in which a second or third language is stored depends on the age of the language learner; whereas each language occupies a distinct area of the brain in an adult learner, language areas overlap in a young child.
(3) 标准书面语中，like/unlike后只加名词(不一定具体名词)表比较，不能加不定式短语,分词短语(prep 1-54 unlike cooking with speices错),句子或介短。（后面接这些东西的时候unlike要改为whereas等等）。
(4) like/unlike是严格的硬梆梆比较，比较对象必须严格对等，中间尽量不能插入任何成分（比如有一个题目是:Unlike A, in 1990 B...就算A，B可比，但这样就是不佳的表达，因为这会让读者花费脑细胞去找unlike和哪个在比。最好的句子一定是排版最严谨、最遵循规则的句子，一定是读起来最省力的句子），但是非限制性定语从句这一类非常明确是紧跟着前面的名词的修饰成分是可以的。
2. 关系代词用法
选项分析：
A. correct；whereas后的介词需要位置上平行对称，在此in mammals和in birds平行；本句比较的是mammals的血管和birds的血管；除了A选项，其他选项结构上都很混乱
B. 虽然whereas不要求对称位置必须是对称名词，但本选项主从句核心含义不对等，一个是tiny tubes的排列，一个是birds用怎么样的tubes，比较主体成了tubes和birds，因此错误；the tiny tubes for the conveying of nutrients to bone cells表达不清晰，不如用定语从句来修饰：the tiny tubes that convey nutrients to bone cells are arrayed
C. mammals和tubes不对等；mammals不是地点、位置，用关系代词where指代mammals错误；the tiny tubes for the conveying of nutrients to bone cells表达不清晰同B
D. mammals和tubes不对等；in whom关系代词错误，要用in which
E. 主句主语tubes前面不能插入in birds，需要改为tubes in birds；which指代cells，原句是the tiny tubes are arrayed in parallel lines，此句变成了bone cells are arrayed in parallel lines，改变句意
补充说明：
1. who, whom只能指人，不可指物（如language，要用which指代）；which只能指物，不可指人
2. 传统语法规定that不能用于指人，而只能用that指思想观点、动物或不具有生命的物体(植物属于不具有生命的物体)，要用whose, whose可以指人也可以指物(prep1-192)
3. OG11-130里面说that不能指代人，只能用who来指代。(虽然现代英语用法中that可以用于不同情形)
4. 本题为OG12-136：OG解释为：
Idiom; Rhetorical construction; Parallelism
Whereas introduces two contrasting situations or events and should be followed by parallel structures. In this sentence, whereas is immediately followed by a clause beginning with the prepositional phrase in mammals; this means that the second part of the sentence must also be a clause that opens with a preposition that functions in the same way—in this case, in birds. This structure clarifies that the things being contrasted are the tubes in mammals and the tubes in birds. Incorrect versions of the sentence grammatically contrast tubes and birds, mammals and tubes, or birds and mammals.
A Correct. Parallel structures make clear that the tubes in mammals are being contrasted with the tubes in birds.
B The faulty parallelism results in a sentence that is confusing and unnecessarily wordy.
C The sentence compares mammals and birds’ ubes.
D Because of faulty parallelism, this sentence also compares mammals and tubes in birds.
E This structure is wordy and confusing because of faulty parallelism.
Th e correct answer is A.
212. (GWD-10-Q1)
According to a survey of graduating medical students conducted by the Association of American Medical Colleges, minority graduates are nearly four times more likely than are other graduates in planning to practice in socioeconomically deprived areas.
A. minority graduates are nearly four times more likely than are other graduates in planning to practice
B. minority graduates are nearly four times more likely than other graduates who plan on practicing
C. minority graduates are nearly four times as likely as other graduates to plan on practicing
D. it is nearly four times more likely that minority graduates rather than other graduates will plan to practice
E. it is nearly four times as likely for minority graduates than other graduates to plan to practice
题目释义：According to…, minority graduates are…four times as likely as…to plan on…
考点：
习惯用语（idiom） 逻辑意思（logical predication）
1. as+adj/adv+as，more than固定搭配：
2. Plan的用法：
plan to do something： He said he planned to write his essay tonight.
plan on doing something： When do you plan on going to Geneva?
plan something： The former president is planning a return to politics.
3. be likely to do 很容易、倾向于做某事。
4. 强调句的结构是：It +be +强调部分+ that (who) + 主谓句。 强调句的连词只有两个，that和who。当强调的部分是人，且为句子的主语时，才用"who"，其余用that。强调句中it无所指。
*：区别强调句型和其他从句的最好方法是“试减法”。也就是说，如果把句子中“It be…that…”这一框架去掉，句子的剩余部分（可以进行位置上的调整）结构完整，意思通顺，合乎逻辑，则that引导的是强调句型，否则为其他从句。例如：It was at nine yesterday that we met the film star.
运用“试减法”，此句可改写为：We met the film star at nine yesterday. 显然，句子结构完整，意思通顺，故为强调句型。
选项分析：
A. 主系表结构的比较中，如果是主语比较，系动词要省略，are多余；be likely in doing用法错误，应为be likely to do…
B. who plan on practicing变成定语从句修饰graduates，使得be likely to结构不完整
C. 正确；four times as likely as…和four times more likely than…都是可以的，且含义相同；Be likely to do...使用正确，plan on doing…使用正确
D. 这里是强调句型，It is likely that…句型可以用(OG 10-237)；more…than比较句型不完整，使得minority graduates不知道和谁比，选项这么写minority graduates一定不是和other graduates比，合适的结构应该是it is X times more likely that A will happen than that B will happen，不过更合适的是'A is X times more likely to happen than B’
E. four times as…than…比较结构错误；for minority graduates和other graduates不平行(将than还原为as后即可发现)
补充说明：
1. 关于倍数的表达----by balabaladou7：
白勇《GMAT语法全解》中说过“...times + 形容词/副词比较级 + than.....”属于有争议的结构，因为产生歧义。标准书面语中避免使用此结构。“....times + as+形容词/副词+as" 则常用。
但好像张道真语法上有说:--6道OG例子证明这个两种表达都可以。
five times as...as 和 five times more/greater than...是表达相同的数量概念的.这是英语国家的语言习惯，不能用中文硬翻理解. 张道真语法 P384/页尾注释。
*：这个语法点manhattan第五版P260上指出来认为两者意思是不同的，一个是5倍一个是6倍，并且比较级的用法是应该避免。大家借鉴性吸收。
2. as或than引导比较从句中的省略原则----form 白勇语法
1) 比较从句谓语与主句谓语相同，可用do，did，does代替。
2) 比较从句连系动词be与主句连系动词be相同，可以省略be，也可以不省略。
3) 主语谓语动词短语使用“助动词（如have，has，had，will）或情态动词（can，could，may，should）+verb”形式时，比较从句往往省略verb，保留助动词或情态动词。
4) 比较从句的主语和谓语与主句的主语和谓语相同时，可以全部省去，常常保留做状语的介词短语或状语从句。
5) 比较从句的主语与主句主语相同，可以省略。
3. It is likely that是可以用的，只是需要看清楚这里的it是形式主语还是指代。
213. (GWD-3-Q34)
Shoppers in sporting goods stores, unlike in department stores, do very little impulse shopping, not buying a pair of skis and a boomerang when they come in for a basketball, but they leave with a basketball only
A. in department stores, do very little impulse shopping, not buying a pair of skis and a boomerang when they come in for a basketball, but they leave with a basketball only
B. in department stores, shop impulsively very little; someone who comes in for a basketball will leave with a basketball only and not also buy a pair of skis and a boomerang as well
C. those in department stores, do very little impulse shopping, do not buy a pair of skis and a boomerang when they come in for a basketball, but leave with only a basketball
D. those in department stores, do very little impulse shopping; someone who comes in for a basketball will leave with a basketball only and not buy a pair of skis and a boomerang as well
E. department stores, shop impulsively very little; someone will not buy a pair of skis and a boomerang when they come in for a basketball but will leave with only a basketball
题目释义：Shoppers in in sporting goods stores, unlike those in department stores, do…；someone…
考点：
比较（comparison） 逻辑意思（logical predication）
1. like/unlike比较对象要绝对对等。
2. 各个分句之间的逻辑关系。
3. 平行对称：not… but…
4. 副词的修饰位置：even修饰比较级时，放在比较级之前。ever放在助动词之后。only、first放在被强调的成分之前，alone放在被强调的成分之后。
选项分析：
A. Unlike后面不可以加介词短语，即便省略也不能省去those；not…but…不平行，应改为but leaving with a basketball only，但这样改了也有but leaving修饰they come in for a basketball的歧义，还是不好
B. Unlike后面不可以加介词短语，即便省略也不能省去those；shop impulsively very little有另一个含义：冲动地买一些小东西(little可以作为adj.，不一定是adv.)，所以还是do very little impulse shopping更明确；also和as well重复；leave with only a basketball强调的是带走的是一个篮球，而不是两个或者更多，而leave with a basketball only强调的是带走的只是篮球
C. do very little impules shopping和do not buy a pair of skis一个是概括，一个是细化，功能不同无法平行，而且but不能连接三个并列成分，只能连接两个，所以即便不考虑逻辑上的层次，do not buy之前也要加上and
D. correct；两个不同层次却有联系的句子用semicolon连接是最合适的。And…as well在此并不重复， as well修饰的是and后面的谓语动词buy（类似见prep 2-166补充说明中对but instead的说明）；Only做adj.修饰basketball
E. shoppers和department stores不对等；shop impulsively very little错误同B；they没有指代；only放在a basketball前强调含义改变，同B
214. (T-9-Q31)
Scholars who once thought Native American literatures were solely oral narratives recorded by missionaries or anthropologists now understand this body of work to consist of both oral literatures and the written works of Native American authors, who have been publishing since 1772.
A. Scholars who once thought Native American literatures were solely oral narratives
B. Scholars thinking of Native American literatures once solely as oral narratives, and
C. Scholars who once had thought of Native American literatures solely as oral narratives and
D. Native American literatures, which some scholars once thought were solely oral narratives
E. Native American literatures, which some scholars once, thinking they were solely oral narratives
题目释义： Scholars who once thought (that) NAL were narratives … now understand…
考点：
句子结构（grammatical construction） 逻辑意思（logical predication）
1. some scholars thought是一种特殊的语法结构，叫做“嵌入式关系分句”，具体见后面补充说明。
2. 过去完成时的使用必须有时间上的参照点，以显示动作发生在过去的过去。
3. 定语从句作定语与分词短语作定语的区别
(1)定语从句强调具体时间具体动作,以及动作的一次性;分词短语强调笼统不确定的时间,抽象/客观/重复性/多次性的行为 à 故定语从句变为分词时会少掉时态
(2)都可以接受时,分词短语优于定语从句(更简洁),定语从句要尽量转换为分词短语(但不能引起歧义)
(3)定语从句包含情态动词时不能转化为分词短语
(4)ing分词的完成时态不能充当名词的定语,必须转化为定语从句n.+ having donen. that…
4. think of sth. as sth.(Longman): to consider that someone or something is a particular thing or has a particular quality
选项分析：
A. correct
B. 用分词短语来代替定语从句去掉了时态指示词；once有修饰solely as oral narratives的歧义；and的插入使得前半句没谓语
C. 过去完成时表示过去的过去，在此没有必要使用过去完成时；think of sth. … as...意思是“把…看作…”，而原句表达的是“认为…是…”，故直接用think (that)更合适；and后recorded修饰对象不明确
D. 未划线部分谓语understand主语成了Native American literatures错误
E. “which some scholars once, thinking they were solely oral narratives”结构混乱，且which引导的定语从句没有谓语。
补充说明：
关于嵌入式关系分句—by tankobe：
OG12-118. The world wildlife fund has declared that global warming, a phenomenon most scientsts agree to be caused by human begings in burning fossil fuels, will create havoc among migratory birds by altering the enviroment in ways harmful to their habitats.
a) A phenomenon most scientists agree to be caused by human beings in burning fossil fuels,
b) a phenomenon most scientists agree that is caused by fossil fuels burned by human beings,
c) a phenomenon that most scientists agree is caused by human beings' burning of fossil fuels
d) which most scientists agree on as phenomenon caused by human beings who burn fossil fuels,
e) which most scientsts agree to be a phenomenon caused by fossil fuels burned by human beings
查了很多贴（国内和国外），对C选项的解释都是半斤八两，看得我一头雾水！（为什么一个定语从句里有两个动词agree和is）
一个普遍的误读是：说most scientists agree 是插入语，虽然是没加逗号！（此解释绝对是误人子弟！！！）
今天我翻遍章振邦的《新编英语语法》（CD上有下载），在1193—1395页赫然发现一个语法词条——嵌入式关系分句，详解如下：
“有一种关系分句（即定语从句），它既是先行项的后置修饰语（即定语），同时又是另外一个分句结构的宾语（即宾语从句）”此分句结构就被嵌入在定语从句中，即嵌入式关系分句。
该书举例：In his breast-pocket he had a patch of scarlet, which i suppose was the paper cap serving as a handkerchief.
注意两点：
1）从句which was the paper cap serving as a handkerchief 首先是 patch of scarlet的定语从句。
2）从句which（patch of scarlet） was the paper cap serving as a handkerchief 也是i suppose 的宾语从句，即I suppose （that）the patch of scarlet was the paper cap serving as a handkerchief 。
综上所述，当一个定语从句同时是另一个主谓结构的宾语从句是，就可以写为嵌入式关系分句。
215. (GWD-3-Q3)
A study by the Ocean Wildlife Campaign urged states to undertake a number of remedies to reverse a decline in the shark population, which includes the establishment of size limits for shark catches, closing state waters for shark fishing during pupping season, and requiring commercial fishers to have federal shark permits.
A. which includes the establishment of size limits for shark catches, closing
B. which includes establishing limits to the size of sharks that can be caught, closing
C. which include the establishment of size limits for shark catches, the closing of
D. including establishing size limits for shark catches, closing
E. including the establishing of limits to the size of sharks that are caught, the closing of
题目释义：A study urged to undertake remedies to…, including establishing…, closing…，and requiring….
考点：
句子结构（grammatical construction） 逻辑意思（logical predication）
1. 定语从句关系代词which的指代
2. and平行结构。
3. limit做动词时的固定搭配：limit to + 界限；limit on doing sth.(做某事的限制)
名词：size limits 大小、规模限制
4. urge的固定搭配：urge sb. to do sth.
5. shark catches: 捕鲨量，此处catch意为a quantity of fish that has been caught at one time
选项分析：
A. which离其逻辑上所指的remedies太远，且如果指代remedies不该用单数includes；the establishment of不如动词establishing简洁，而且与后面的closing不平行。
B. which和includes错误同A；limits to the size of sharks that can be caught不够简洁，直接用size limits和shark catches就行
C. which错误同A；the establishment of和the closing of名词短语不简洁且和requiring不平行
D. correct；including修饰remedies，including是介词，其跳跃能力比which强
E. limits to the size of sharks that can be caught不够简洁，直接用size limits和shark catches就行；the establishment of和the closing of名词短语不简洁且和requiring不平行
216. (T-3-Q39) (天山-7-39, OG12-18)
Plants are more efficient at acquiring carbon than are fungi, in the form of carbon dioxide, and converting it to energy-rich sugars.
A. Plants are more efficient at acquiring carbon than are fungi,
B. Plants are more efficient at acquiring carbon than fungi,
C. Plants are more efficient than fungi at acquiring carbon,
D. Plants, more efficient than fungi at acquiring carbon,
E. Plants acquire carbon more efficiently than fungi,
题目释义：Ps are more efficient than Fs at doing sth., …, and doing sth. …
考点：
比较（comparison） 逻辑意思（logical predication）
1. 比较双方要对等。
选项分析：
A. 后面的in the form of carbon dioxide错误的修饰了fungi；converting应当与acquiring平行
B. Than后面需要补出are，否则有acquiring fungi的歧义；后面的in the form of carbon dioxide错误的修饰了fungi；converting应当与acquiring平行
C. Correct；in the form of carbon dioxide修饰carbon
D. “, more efficient than fungi at acquiring carbon,”作为插入语，使得句子没有谓语东西，并且and没有平行对象
E. 比较对象错误会导致carbon与fungi对比的歧义；修饰错误同A
补充说明：
1. OG12-18解释
Logical predication; Grammatical construction
This sentence compares how efficiently plants and fungi acquire carbon and convert it into sugars. The sentence construction needs to make clear that plants and fungi are the two topics being compared, and it must also clarify that in the form of carbon dioxide refers to carbon rather than to either plants or fungi.
A According to the sentence grammar, in the form of carbon dioxide describes fungi, which is nonsensical.
B This sentence claims that plants acquire carbon more efficiently than they acquire fungi, which is also nonsensical; the form of carbon dioxide still modifies fungi.
C Correct. The sentence clearly compares plants to fungi, and in the form of carbon dioxide correctly modifies carbon.
D This sentence is grammatically incomplete; there is no verb for the subject plants.
E As in B, this sentence claims that plants acquire carbon more efficiently than they acquire fungi; it is also grammatically incomplete because and converting does not clearly refer to anything.
The correct answer is C.
2. 关于比较，摘自prep笔记1-128。
比较-主语比较
1. 对主谓宾全的句型主语比较：A do sth than B do.（AB为对等名词，加do是为了显示这是一个可以发出动作的名词，因而确定是主语，进而确定是主语对比）。时态要据后定。There be 句型等同于一般的主谓宾俱全的句型。
主语若相同，可省，但助动词不能省。如：
As a result of the continuing decline in the birth rate, [fewer people] will enter the labor force [in the 1980’s] than (people省略) did [in the 1960’s and 1970’s], a twenty-year period during which people born after the war swelled the ranks of workers.
2. 对只有主谓（如果主语有定语成分，必须要that/those来指代），没有宾语的句子，因为没有宾语，只可能有主语比较，因而不需要重复do来确认这是一个可发出动作的主语，所以其比较形式如下：
I eat faster than you.注意与下句区别 I eat apple faster than you do 如果写成 I eat apple faster than you 按GMAC的理解，从语法上就变成我吃苹果比吃你快，成了宾语比较。逻辑上显然不通。
3. 主系表结构的比较与主谓结构相同。如果时态不一致，则需补出助词，如：
The economy of Florida is more diversified than it was ten years ago
217. (T-3-Q17) (天山-7-14)
Not one of the potential investors is expected to make an offer to buy First Interstate Bank until a merger agreement is signed that includes a provision for penalties if the deal were not to be concluded.
A. is expected to make an offer to buy First Interstate Bank until a merger agreement is signed that includes a provision for penalties if the deal were
B. is expected to make an offer for buying First Interstate Bank until they sign a merger agreement including a provision for penalties if the deal was
C. is expected to make an offer to buy First Interstate Bank until a merger agreement be signed by them with a provision for penalties if the deal were
D. are expected to make an offer for buying First Interstate Bank until it signs a merger agreement with a provision for penalties included if the deal was
E. are expected to be making an offer to buy First Interstate Bank until they sign a merger agreement including a provision for penalties if the deal were
题目释义：Not one of n.s is expected to do sth. until a MA is signed that includes a provision for penalties if the deal were not to be concluded.
考点：
主谓一致（agreement） 习惯用语（idiom）
1. (not) one of the+名词复数+单数形式谓语；Not one of =none of。
2. 虚拟语气：与将来事实相反，条件从句的谓语be动词一律用were to+动词原形。
3. 被动语态未必比主动语态差，被动语态有其特殊功能，比如可以避免写出动作发出者来避免错误或累赘。
选项分析：
A. Correct；a merger agreement引导的句子并不是if the deal were的主句，If the deal were中的If可以理解为“in case (that)”，后接虚拟语气，由此可见虚拟条件句不一定非要虚拟主句才能使用（if the deal were这个用法其实也和if any类似，作为独立成分出现在句中）；a merger agreement is signed that includes中that没有直接与a merger agreement相邻而且跳过了谓语动词修饰，这说明关系代词短距离跳跃指代是允许的
B. 表示动作的目的用to do比for buying更好，表示一个动作趋向；they无指代；虚拟语气用用was错误
C. be signed时态错误；with a provision修饰be signed，意思成了需要一个条例来规范”签署”这一动作，而不再是签署有这一条例的协议；them和an offer单复数不匹配，一个投资者只能有一个offer，并不需要写出by them
D. are错误，主谓不一致；For buying错误同B；虚拟语气用was错误；It无指代
E. are错误，主谓不一致；they和an offer单复数不匹配，一个投资者只能有一个offer，选项这么写好像在说只要一有投资者，那么所有的潜在投资者都要签署agreement，所以最好的写法是通过被动语态来避免直接写出动作行使者
补充说明：
1. 关于定语从句的关系代词能否跨越谓语动词指代：如果关系代词与先行词相隔较短，关系代词能跨越谓语动词指代，如本句a merger agreement is signed that includes a provision。
2. 关于none of(by windmaple)：None可以等于not one（动词用单数），也可以等于not any（动词用复数），这个是有争论的，Manhattan Review SC上的SANAM说none要看情况定动词单复数；manhattan forum上的结论是：因为none在OG里面从来没用过复数动词，所以大家还是选单数吧。
218. (GWD7-Q4)
Only seven people this century have been killed by the great white shark, the man-eater of the movies—less than those killed by bee stings.
A. movies—less than those
B. movies—fewer than have been
C. movies, which is less than those
D. movies, a number lower than the people
E. movies, fewer than the ones
题目释义：Only seven people this century have been killed by … --- fewer than have been killed…
考点：
比较（comparison） 习惯用法（idiom）
1. 比较双方对等。
2. people作为人民讲的时候是复数名词，所以用few不用little。
3. 破折号在本题中有反讽或表达意外的含义：被蜜蜂蛰死的人比被专门吃人的白鲨吃掉的人还多。破折号其他用法见prep 1-182
4. as,than可以做比较从句的主语(见prep 1-202)
选项分析：
A. less错误，seven people是复数概念，要用fewer修饰。比较的是一个带有数值概念的复数名词seven people，后文用those仅仅指代了people，失去了”数值概念”，所以是错误的，唯一一个好的解决方法是than后面省略主语，后面补出have been，让省略的主语自动拥有”数值”属性
B. correct；than可以即做连词又做代词（当然还可以做介词），即than作为比较连词的同时指代了people(见prep 1-202)；另外破折号的使用是适合的
C. which指代了the great white shark(或者也可以说是指代man-eater，其实逻辑上无区别，所以可以说是指代等价的)，使得逻辑错误，并不是shark less than…而应该是人数更少，应该是seven people are fewer than…；less错误，同A；than后面要用have been（同A）
D. a number同位语与其所修饰对象seven people太远；number不能跟people相比较，因为单纯的people并没有”数值属性”
E. the ones没有”数值”概念，无法与seven进行数值上的比较；than后面应该用句子与前面意群平行。
补充说明：
关于比较
aeoluseros
比较结构是SC里面的重中之重与必考知识点。比较虽然只是一个知识点，但其考法变化多样，一会谓语比较，一会主语比较，一会状语比较，而在比较中还要看比较双方是否具有可比性，比较结构中是否可以省略等等。GMAT对于比较也一直没有非常明确的用法说明：什么样的形式是可以接受，什么样的则不可以。即便分析完所有自从大全到OG12的题目，也难下定论说以后比较的考法，以后不会再出新的花样。不过不论如何，到现在位置比较题出现了不下百次，对上百个比较题的分析让我们多少也能对GMAT的态度窥视一二。不同的人看待比较的视角不同，可能有不同的解释，但是就如果股市里的技术指标一样，我们不是追求看法的绝对正确性，而是追求该看法、观点是否适合自己，是否能让自己获利、做对题。当然，我们GMAT语法里的不确定性远远比那些股市技术指标要小，因此多看一些前辈关于比较的总结，我们或许能得出几乎接近”真理”的比较题做法。我在此列出的观点亦仅代表个人，予大家以批判参考。
OG10-19. In addition to having more protein than wheat does, the protein in rice is higher quality than that in wheat, with more of the amino acids essential to the human diet.
(A) the protein in rice is higher quality than that in
(B) rice has protein of higher quality than that in
(C) the protein in rice is higher in quality than it is in
(D) rice protein is higher in quality than it is in
(E) rice has a protein higher in quality than
In this sentence, the initial clause modifies the nearest noun, identifying it as the thing being compared with wheat. By making protein the noun modified, choices A, C, and D illogically compare wheat with protein(是指In addition to having more protein than wheat does这个从句里面) and claim that the protein in rice has more protein than wheat does. In C and D, the comparative structure higher in quality than it is in wheat absurdly suggests that rice protein contains wheat. B, the best choice, logically compares wheat to rice by placing the noun rice immediately after the initial clause. B also uses that to refer to protein in making the comparison between the proteins of rice and wheat. Choice E needs either that in or does after wheat to make a complete and logical comparison.
从E可以看出，用than that in wheat或than does wheat都可以，
但这并不能说明在其他的比较结构中也能用that in，而不是用主谓(宾)结构来与than前面的结构平行。在这个句子里：Only seven people this century have been killed by the great white shark, the man-eater of the movies—fewer than have been killed by bee stings.后面的比较成分是不可以改为less than those killed by bee stings的。具体原因如下：
在rice has a protein higher in quality than that in wheat这个句子里，比较对象是protein和that（that指代的也是protein），比较的仅仅是protein（rice has不在比较成分之内，比较的是protein的属性），所以允许平行。而在Only seven people this century have been killed by the great white shark, the man-eater of the movies—fewer than …中，不仅仅Only seven people，后面的this century have been killed by the great white shark也都在比较对象里面，所以后文不能用those killed by bee stings，而应该用平行的结构than have been killed。
再比如这个句子(GWD-29-24)：According to recent studies comparing the nutritional value of meat from wild animals and meat from domesticated animals, wild animals have less total fat than (that of) livestock fed on grain and more of a kind of fat thought to be good for cardiac health. 这个句子不对。其在livestock前加上that of…比较的对象是animals has less fat和that，that指代fat，而事实上比较的应该是wild animals和livestock的属性，即拥有fat的多少，所以than后面也应该用平行的句式，即主谓宾形式。正确句子为：According to recent studies comparing the nutritional value of meat from wild animals and meat from domesticated animals, wild animals have less total fat than livestock fed on grain and more of a kind of fat thought to be good for cardiac health.。要注意的一点：在此省略了相同的谓语和宾语（因为不会有wild animals have livestock的歧义，只要逻辑上基本成立，GMAT并不认为所有没有补出谓语动词的形式都是”ambiguities”的）。（原句不对的另外一个证据： more of a kind of fat 后面省略了(than…)，而省略的部分应该和less total fat than后面的词句是一致的，这样才能省略逻辑上看省略的必须是livestock，而不能是that of livestock，因此less total fat than后面跟的也应该是livestock。）
219. (GWD-12-Q20)
Approved April 24, 1800, the act of Congress that made provision for the removal of the government of the United States to the new federal city, Washington, D.C., also established the Library of Congress.
A. Approved April 24, 1800, the act of Congress that made provision for the removal of the government of the United States to the new federal city, Washington, D.C., also established
B. The act of Congress, which was approved April 24, 1800, making provision for the removal of the government of the United States to the new federal city, Washington, D.C., also established
C. The act of Congress approved April 24, 1800, which made provision for the removal of the government of the United States to the new federal city, Washington, D.C., and established
D. Approved April 24, 1800, making provision for the removal of the government of the United States to the new federal city, Washington, D.C., the act of Congress also established
E. Approved April 24, 1800, the act of Congress made provision for the removal of the government of the United States to the new federal city, Washington, D.C., also establishing
题目释义：Approved April 24, 1800, the act of Congress that made provision for sth…., also established
考点：
逻辑意思（logical predication） 句子结构（grammatical construction）
1. 逻辑主语。
2. The acts of Congress：国会立法案(act不需要大写)，有public laws，也有private laws。本题只要理解国会立法案不仅仅只有一个就能作出答案。
3. 限定性修饰与非限定性修饰的区别。
选项分析：
A. Correct；the act of Congress是主语也是逻辑主语；法律法规的具体的内容要用ving修饰，比如法规规定捕的鱼必须小于一定尺寸，但此处made provision for the removal of the government of the United States to the new federal city, Washington, D.C.意为“提供了政府迁移的相关条款”，并没有说明法律法规的具体内容，所以限定性定从更合适。
B. that引导的限定性定语从句不能被改为which引导的非限定性定语从句，因为“谈论的立法案是特指搬迁首都的那个”，因此必须用that引导的非限制性定语从句（如果用which引导的非限定性定语从句，则imply了“国会立法案就只有1800年颁布的那一个”，违背常识）；making作为伴随approved的结果状语，逻辑意思不合理，其应该是说明act的作用，修饰act
C. which指代太远不及A好；and的插入使得前面分句没有谓语，后面分句没有主语。
D. 主语前面部分冗长awkward；making作为非限定性修饰，使得句子表达的是act of Congress只有那么一个，违背常识。
E. The act of Congress少了限定性定语从句的修饰，使得句子表达的是act of Congress只有那么一个，违背常识；establish和make provision逻辑上是同一层次的，不应该把establish作为伴随结果(逻辑含义也变得不合理)，所以要不把also establishing改为and also establish，要不改为同A选项一样。
220. (GWD-24-8, OG12-86)
The results of the company's cost-cutting measures are evident in its profits, which increased five percent during the first three months of this year after it fell over the last two years.
A. which increased five percent during the first three months of this year after it fell
B. which had increased five percent during the first three months of this year after it had fallen
C. which have increased five percent during the first three months of this year after falling
D. with a five percent increase during the first three months of this year after falling
E. with a five percent increase during the first three months of this year after having fallen
题目释义：The results … are evident in its profits, which have increased 5% during the first three months of this year…
考点：
句子结构（grammatical construction） 逻辑意思（logical predication）
1. with独立主格结构：
由“with ＋宾语＋宾补”构成的复合结构，在句中可作状语，表示伴随。这一结构中的宾语补足语可由现在分词、过去分词、不定式、形容词、副词或介词短语等来充当：
E.g.: Visitors to the park have often looked into the leafy canopy and seen monkeys sleeping on the branches, with arms and legs hanging like socks on a clothesline.
E.g.: He used to sleep, with the door open. 他过去常开着门睡觉。（形容词）
E.g.: With a boy leading the way，they started towards the village. （现在分词）
E.g.: With the work done，he went home. （过去分词）
E.g.: With you to help us，we will finish the task in time. （不定式）
2. 时态问题。
3. AlienX: after having done something是不可能对的
1) after已表示the sequence of events. 没有必要用having done来表示前后
2) 可是after someone/something has/have done something是acceptable; 如果变成after someone/something did something也可以
选项分析：
A. Increased和have increased都可以，只是表达的意义不同，如果这句话写于今年3月底，那么就用have increased，要是写于4月及以后就用increased(此处与OG12的解释略有不同)；it指代profits单复数错误；after it fell应该用after it had fallen与over the last two years搭配，但是不如after falling简洁
B. it错误同A；时态错误，主句用are evident一般现在时，从句和主句时间上不能有gap(manhattan SC #4 P111)，因此从句不能用过去完成时which had increased，正确写法应该是which have increased
C. Correct；after falling简洁，状语从句的省略
D. with独立主格修饰前面的分句，而不是its profits，修饰错误；falling的逻辑主语也成了results，错误。
E. with错误同D；after having done错误。
补充说明：
OG12-86解释
Verb form; Agreement; Idiom
This sentence describes two sequentially ordered indicators by which the results of a company’s cost cutting measures can be seen. The first indicator to be identified, a 5 percent increase in profits, occurred after the indicator mentioned next. The sentence therefore needs to clarify the sequence by presenting the first-identified indicator in a clause with a verb tense that indicates a later time period than the verb tense in the clause presenting the second-identified indicator(动词时态区分动作先后顺序). The subject of the relative clause, which, refers to the plural noun profits, so subsequent pronouns referring to these profits must also be plural.
A The verb tenses do not distinguish between the times at which these indicators occurred; the singular it does not agree with the plural profits.
B The verb tenses do not distinguish between the times when the indicators occurred; the singular it does not agree with the plural profits.
C Correct. The verb tenses clearly indicate the sequence of events.
D It is not clear what connection is being described by with; the prepositional phrase makes the sentence wordy and unclear.
E It is not clear what connection is being described by with; the prepositional phrase makes the sentence
wordy and unclear.
