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

用时太长了！考试估计要直接跳过了。图太有误导性。利用了等腰三角形底边高与底边中分线是同一条线的性质，所以AC和CE在一条线上。BD垂直AC，所以直接底乘高除2 可得

感觉E，C更像是只是重复了前提。E是将更不关注钱和解题时不合作/求助建立因果关系，也正是结论想说的

太难了这套

是因为so可以指代句子，it只能指代名词吗

难道是因为问题里面用了"separately supported..by passage and 2 tables"? 所以虽然passage是完全support的，但是table里面完全没有涉及，所以只能选No？

生厂商白嫖了兽医提供的有效的营销渠道，但是兽医没有得到全部好处

为什么很多好的题目都没有讲解。。。。。。烦

C选项为什么不对呢

prove主动被动都对
有时间终点用名词形式，否则用动名词形势