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设男性人数为x，女性人数为50000-x，则在列出生在town x的人数的式子为：0.6x+0.6*(50000-x)=0.6*50000，0.6x在式子中是可以消掉的，所以结合可求C

with a maximum radius -->没有告诉最小的radius是多少，因此无法判断，排除

for the first 300 positive integer multiples of 5：在前300个以5为倍数的数字中，即以5为首项，5为等差，构造等差数列，则第300项为1500，范围为5~1500
求5出现的次数：分为个位数，十位数，百位数的5出现次数来求

这道题最好做的方式是取反，取反E：在疫苗没被污染的F，M病样本中也有SV40
削弱了

十位数调动总和会变，个位数调总和不会变-->所以50不是最大的，59才是

少 逗号？

Like = used to compare two nouns; the word after “like” should be a noun
As = used to compare two actions or verbs; the work after “as” can be either a noun or verb
(Note: ”like” and “similar to” are the same thing, and follow the same rules)

注意being有同时性，而句中没有明显同时发生的标志，不选；
BE是conviction of genes不正确
前后两句话只要有转折关系即可

没有明显的完成时标识，不要乱选完成时选项！！

注意比较对象不是41 millions of tons【其中tons是计量单位unit nouns，不是复数名词】,而是rice production，所以是不可数对象比较；those of 在此处没有指代对象，排除
C选项：直接把1978和rice production相比较，错误

mark 代词
注意 do so VS do it

弄清楚比较主体
是句子VS句子的比较
doing sth is a goal of sb, as it was of sb
【引用】
-这里是不同时代的比较,基本结构是doing something is a goal of sb,as it was (a goal)of sb.
-Like是接名詞,as要接子句.使用Like只能进行主语比较。 如果主句的主语是个名词，可以用like + n；如果主句主语是个doing ... ，就不要用like了，因为不能平行，要用as 引导句子；
2.it指代的是前后是同一个东西，that指代的是同一类，但前后东西不一样.
这里面owing and living in a house这个dream是不同代人的同一个梦想，因此用it,而不是that!
C: as+句子正确，但是用did替换is a goal前面不平行一致

A 半导体行业对于专利的方法获得了意料之外的结果【其实文章在开头两句就指出关系发生了变化，且半导体行业的approach是例子里面的内容，没有选项C更直接】
C研究半导体行业的专利和创新的关系

Because the source of a hot spot remains fixed while a surface plate moves over it, 【over a long period of time】 an active plume creates a chain of volcanoes or volcanic islands,
AE未提及；C选项指的是大多数火山爆发的情况；D选项提到了many other chains，实际原文只说到了a chain，错误；

Because of its proximity to Earth's core, 核心词mantle-->reservoir-->plume-->hot spot
The surface mark of an established plume is a hot spot E选项正确
A选项提及untapped，未开发的plume，定位句[The "mantle plume" thus formed, once established, continues to channel hot material from the mantle base until the reservoir is emptied. ]错误
BC指的都是大多数火山爆发的情况，并非考察文段中少数火山爆发的情况；
D选项全文未提到，排除

5. In the nation of Partoria, large trucks currently account for 6 percent of miles driven on Partoria’s roads but
are involved in 12 percent of all highway fatalities. The very largest trucks—those with three trailers—had less
than a third of the accident rate of single- and double-trailer trucks. Clearly, therefore, one way for Partoria to
reduce highway deaths would be to require shippers to increase their use of triple-trailer trucks.
Which of the following, if true, most seriously weakens the argument?
(A) No matter what changes Partoria makes in the regulation of trucking, it will have to keep some smaller
roads off-limits to all large trucks.
(B) So far only the best, most experienced drivers for Partorian trucking companies have been driving tripletrailer trucks.
(C) Very few fatal collisions involving trucks in Partoria are collisions between two trucks.
(D) In Partoria, the safety record of the trucking industry as a whole has improved slightly over the past ten
years.
(E) In Partoria, the maximum legal payload of a triple-trailer truck is less than three times the maximum legal
payload of the largest of the single-trailer trucks.
这道题为什么选B呢？

farmer的目的是杀死害虫，但是这两种药的缺点是还没达到致命剂量就无法进食了，虫子没法继续吃毒死去，无法有效达到farmer的目的。

1) 在GMAT考试用只能用whether表示“是否“,不能用if

2) when不能够引导条件从句

3) 习惯用语:in depth

(A) if应该改成whether;使用when从句来表示条件从句,错误

(B) if应该改为whether; with as much depth不符合习惯用法

(C) It is unclear whether… or would…结构不平行

(D) similar patterns would be exhibited in other animals表达笨拙,应该改为主动语态;with as much depth不符合习惯用法;用that限定性定语从句修饰animals无法表达出条件关系,改变了句子的合理意思 大仙注释：其实就是尊重前半截即可，前半截用主动

(E) 正确, It is unclear whether… or whether…结构平行;用语简洁,符合习惯用法;使用if从句表达条件关系,符合句子的逻辑意思

这道题是选C的吧，在别的论坛上看都是C，文章也完全没有提男人和女人的经济行为有没有变得更varied的，有的只是说男人的行为要变得更广泛，走向了外地； 而且，全文都在围绕commercial interests and credit networks，如果是varied，应该讲他们的经济行为变得更多样了（比如说买债券买股票买保险blabla）；这个less varied 也很有问题。
C对应原文： in fact, both the absolute numbers and the percentage of adult women participating in civil cases grew steadily throughout the eighteenth century, but the legal activity of men also increased dramatically, and at a much faster rate.

At the same time, women's networks of credit and debt remained primarily local and personal. --女性更关注本地、私人的debt
Dayton contends that, although still performing crucial economic services in their communities—services that ontributed to the commercialization of the colonial economy—women remained for the most part outside the new economic and legal culture of the eighteenth century.--女性依旧被排除在外
用排除法选择
mark