E的逗号没有问题，问题在于decrease in size与后面的l形容词less distinctive， less in demand不能很好地组成平行结构

choice b "having" + "was ineffective" doesn't make sense.

"having" adopts the same timeframe as the rest of the sentence -- which is the present (we can discern this by noticing that the sentence is talking about patients who do not respond). however, "was ineffective" seems to suggest that the prescription was ineffective sometime in the past.
taken together, these two contexts seem to indicate that the patient is, for some reason, holding onto an old prescription that was ineffective.

choice c would be incorrect because of Parallelism as well. Note that "as" creates a comparison, which is a special case of P-ism. Here the "as" connects "having too low a dosage" with "treatment." The same is the case with E, in a way, as the example give is not an example of a "treatment."

in choice d
1. "It" is ambiguous (original sentence without "It" sounds better)
2. Lack of parallelism "have been" not parallel to "were"
3. "too low a drug dosage" sounds awkwardly at least.

Choice d and e："when" doesn't really work, because the sentence is talking about the things that are actually examples of inappropriate treatment.

Choice a：'the national average' would be exactly what it says: an average.
i.e., some kind of statistic.
it is not a person, so that option is nonsense.
Choice e：we do not have "subject is likely that-clause" in english。

choice a the comparison made in choice a is ok. the real problems with choice a:
- 'the ratio of 42 times' is redundant; it'd be good enough just to say '42 times'. note that the word 'ratio' is not redundant in choices c-d, since it's being used as a modifier to make a logical connection.
- it doesn't say 42 times what. not only is that unacceptably vague, but it also breaks parallelism.

choice b is badly worded: 'compares to 42 times in 1980' seems to say that, on forty-two different occasions in 1980, the ceo:blue-collar ratio reached 419:1. this is not what we are trying to say.
more generally, when speaking about ratios as is done here, you can't just write "42 times" by itself. it has to be 42 times something. sometimes you can use pronouns - the height of the sears tower is more than four times that of the statue of liberty - but you can't use empty space.

choice c exhibits proper usage of 'times' followed by their pay. it also uses the ratio, a correct identification of exactly what is being described.

the construction in choice e doesn't make sense.since that's obviously not the case here——the report points out a fact about these CEOs, not the identities of the CEOs themselves。

条件2说的是折叠后的梯形面积，我是设的边长为2a，这样好算一点

折叠后的梯形面积就是(3√3·a^2)，让这个数小于36，算得a^2小于4√3，可以粗略算出a小于2.6或大于-2.6，因为是边长所以取区间（0，2.6）

如果a=2.6，折叠后梯形下底边长是4a，所以4*2.6=11.4，大于9，不行；如果a=2，4*2=8，小于9，行。

所以条件2不充分

这人不会说中文的吗， 我寻思不是写着中文名呢吗，有点意思

建议翻译过去式的时候，都翻译成曾经怎么怎么样，曾经怎么怎么过，这样不太容易错

* Modifiers like "...(that) they are aware of" are not ok in formal English; you'd want "of which they are aware" (or something totally different, e.g., "that they know") instead.
Similarly:
the person I spoke to --> no; the person to whom I spoke --> yes.
the stores (that) most people shop at --> no; the stores at which most people shop --> yes.
The "no"s here are worth noticing because they are cornerstones of SPOKEN English (i.e., an altogether different language). If English isn't your first language, then avoiding these will, ironically, be much easier than if it were.

"There is / there are..." is just another way of saying that things exist, or that they are in a certain place.

It's certainly not a way of expressing emphasis. As far as the GMAT is concerned, there's no difference between "there are Xs" and "Xs exist", and there's no difference between "there are Xs in this place" and "Xs are in this place".

---- YOU DON'T NEED TO KNOW ANYTHING BELOW THIS LINE FOR THE TEST ----

In terms of the GMAT, as I stated above the line, there's no difference.

In general usage, in fact, the construction without "there is/are" is generally more emphatic.
e.g.,
Mr. Wong, there are two people in your office. --> ok, we're just counting people, presumably for some reason mentioned earlier in the conversation.
Mr. Wong, two people are in your office. --> I specifically want to draw your attention to the people. "They want to see you", or "You should be aware that they're there; maybe you don't want them there."

i maintain that the principal issue with choice (a) is unrelated to the "with" issue. instead, the primary problem with (a) lies in its meaning.

* According to the sentence, the companies are intentionally avoiding the use of "A", "B", "1", "2", etc. So, common sense dictates that they're aware of the reason; they are certainly not avoiding those labels at random!

the problem with (a) is that it says only that companies are aware "that there are connotations". in other words, literally, the companies just know that there are connotations -- in other words, that connotations (of some sort) exist -- but the companies don't necessarily know what those connotations are.
the correct answer, on the other hand, explicitly states that the companies are "aware of the connotations" -- i.e., aware of the actual nature of those connotations.

analogy:
i am aware that discounts are available this weekend.
--> i know that there ARE discounts, but i don't necessarily know the specifics.
i am aware of the discounts available this weekend.
--> i actually know the specifics (percentages or whatever) of the discounts.

* (A), (C), and (E) don't deliver the intended meaning.
I.e., these choices don't actually say that the companies know what the connotations are. It just says that the companies know "that there are connotations".
This is a HUGE difference. If the distinction is not immediately obvious to you, consider the following sentences:
1/ I know that there are passwords for all of your bank accounts.
2/ I know the passwords for all of your bank accounts.

Parallelism is not the key differentiator between (c) and (d).
--
there are two problems i see in (d).
--
problem #1

a substance to promote... is unidiomatic.
the only context in which i can remember "a NOUN to VERB" is a context in which the NOUN is abstract in nature. for instance:
a way to produce goods
a reason to try harder
etc.
note that "substance" is a concrete item; it's not an abstraction like "way" or "reason".

if you're talking about concrete objects, you should replace the infinitive with something else. for instance:
* a substance to promote X (incorrect) --> a substance that promotes X (correct)
* a tool to install the shelves (incorrect) --> a tool with which to install the shelves (correct)
--
problem #2

"which is" is unnecessary and ugly.

if "which is" is followed by a description of something, you should just omit it, producing an appositive modifier:
X, which is a substance... (ugly) --> X, a substance... (better)
Person X, who is the coach of Team Y (ugly) --> Person X, the coach of Team Y (better)

问assumption， 那么就是其中的一个选项会使得计划行得通，那么选项E, 如果扫描打印能打印的很小，那么这个方案就行不通了。

主谓一致看错了

理解选项意思：
C 说明这种猴子相比其他猴子更容易受刺激会攻击，这就说明它已经代表了总体中最麻烦最极端的一种，连它都没问题了，任何其他的也就没问题了。

E选项：介词短语with higher-than-average blood pressure和with a history of high blood pressure running in their family之间缺少连词连接，正确方式为：
young people with higher-than-average blood pressure and with a history of high blood pressure running in their family are more likely than others to develop a severe form of the condition.

C 文章中未提及

A: as a result of several improvements和because coal replaced charcoal as the fuel used in the smelting of iron ore并列。语法上是可以的，因为两者都是原因状语

错选C：文章说的是Krech also contradicts Martin's exclusion of climatic change as an explanation by asserting that widespread climatic change did indeed occur at the end of the Pleistocene.就是说K认为M不该排除天气变化是灭绝的一个原因，因为K认为波及范围广的天气变化确实在end of the P的时候发生了。
那么答案说Additional evidence indicating that widespread climatic change occurred not only at the end of the Pleistocene era but also in previous and subsequent eras. 其它时候有没有发生和end的时候有没有发生无关。

文章：small animals, plants, and insects disappeared, presumably not all through human consumption。 并不都是
B：Paleoindians made use of the small animals, plants, and insects that became extinct 是人的使用导致的，削弱



我脑补了，如果在这之前就有气候变化，那么动物早该灭绝了。。。TAT

最小公倍数就是取最大指数的质因数

3/3*2/3*1/3=2/9
3*2*1/A33