for anybody who wants to know the answer, --- by Ron
probably the easiest way to go here is to remember this as an idiomatic usage of the construction "known to". if the action is in the present, then you use "known to VERB"; if the action is in the past, then you use "known to have VERBed". as far as i know, these are the only two possible forms.
Sulfur dioxide, a major contributor to acid rain, is an 【especially】 serious pollutant because it diminishes 【the respiratory system's ability to deal with all other pollutants】.
二氧化硫是酸雨的主要贡献者，是一种特别严重的污染物，因为它会降低呼吸系统处理所有其他污染物的能力。
1. capability to do（√）； capability of/in doing（×）；
2. capable of doing （√）
3. sb's ability to do sth （√），ability of sb/sth to do sth （√）
4. capability to do不如ability to do简洁，但不可就此判错。
选项C（√）
Over 75 percent of the energy produced in France derives from nuclear power,--主谓宾
whereas nuclear power accounts for just over 33 percent of the energy produced in Germany.--主谓宾
法国 75% 以上的能源来自核能，而核能仅占德国能源的 33% 以上
选项D（×）
Over 75 percent of 【the energy】 produced in France derives from nuclear power,
whereas just over 33 percent of 【the （×）energy ∵不是同个energy】 comes from nuclear power 【in Germany（×）位置不对，应该在energy后面】.
the energy前的定冠词the表示这个energy指代前面出现过的energy，即，生产于法国的核能，in Germany位置变成了修饰nuclear power，这句话的意思变成了“在法国，超过33%的能量来自于德国生产的核能”，失去了比较的意义
more babies were born to women over the age of thirty
than (babies were born to women省略相同的S+V) under it（指代the age of thirty）
According to public health officials, in 1998 Massachusetts became the first state in which more babies were born to women over the age of thirty than under it.
据公共卫生官员称，1998 年，马萨诸塞州成为第一个 30 岁以上女性所生婴儿多于 30 岁以下女性（所生婴儿）的州。
A. correct； than后面省略了babies born to women； 因为under与over的平行， it明确指代the age of thirty.(换句话说， 有了Under就能知道than后面省略的是women了，不用像C补出they were了)
B. under it修饰了born，逻辑意思荒谬：孩子们生下来时小于30岁。
C. 根据比较的平行 they 指代 babies，但仅补出 they were 使得 were 是助动词还是系动词不清楚，系动词 的话， under it 修饰了 they，逻辑错误，助动词的话， they were 累赘。
（they 仅指向 babies 而不是指 向 30 岁以上母亲剩下的 babies，类似的例子如： In Japan elderly people are treated with far greater
respect than they are in most Western countries.they 不是指代 Japan 的老年人，而是就老年人）
D. had时态错误，比较双方是同时发生的，应该都用一般过去时； there无并列对象。
E. had时态错误同D
Prospecting for gold during the California gold rush was a relatively easy task, 【since 】erosion*, prehistoric glacier movement*, and ancient, gold-bearing riverbeds* （thrust to the surface by volcanic activity）【put 】gold literally 【within reach of】 anybody with a pan or shovel.
在加利福尼亚淘金热期间寻找黄金是一件相对容易的事情，【因为】侵蚀、史前冰川运动、（被火山运动推到地表来的）古老的产金河床，使任何人用平底锅或铲子都可以【接触到】黄金。
reach for sth.：伸手抓某物；
reach of sb.：在某人能触及到的范围内--【within reach of】 anybody
D选项：rate的of型所有格中（做rate的定语）的核心词是fatty foods（consumed in France and the United States是过去分词短语）。在逻辑上，具有相同比率的应该是两个国家人消耗食物这件事情，而不是食物本身拥有比率（食物自己没法有比率）。另外，通常，the rate of food指代的是“食物的价格”。本选项在语意上显然不是“食物的价格在美国法国相同”。
the REAL issue, though, is "unqualifying" -- this is incorrect. "unqualifying" means "not meeting some sort of standard for qualification".
the intended meaning here is "unqualified", which means "without any sort of restriction or reservation". 无条件的
Ron： i'm loath to use apostrophe + "s" for anything but humans, animals, and the like. ‘s’更偏向一个人
(a)
"so that" is wordy, but also doesn't make literal sense here -- "X so that Y" implies that X is an action taken toward the goal Y. i.e., i studied hard so that i could get a good grade.
needing time is not an action taken toward a goal, so this doesn't make sense.
(b)
read literally, this sentence doesn't give any indication that the workers themselves need the time -- it just states that the time is "needed" (we don't know by whom) when the workers are working.
with a thesis that is a simple one：介词短语作为状语，修饰前面的动作v.-- publish （语义不通）
whose thesis was simple: consumers have：定语从句修饰前面的名词n. --Shopping for a Better World. （语义合理）
In 1988, the Council on Economic Priorities began publishing 【Shopping for a Better World, whose thesis】 was simple: consumers have the power to change companies by the simple expedient of refusing to buy.
1988 年，经济优先委员会开始出版《为更美好的世界而购物》，《为更美好的世界而购物》的论点很简单：消费者有权通过拒绝购买的简单权宜之计改变公司。
such：
作代词，指代前面提过的东西或事情，如：
She longed to find somebody who understood her problems, and in him she thought she had found such a person. 她渴望找一个理解她困难的人，她觉得他就是这样一个人。
Accountants were boring. Such was her opinion before meeting Ian! 做会计的个个乏味。在认识伊恩以前她一直这样想。
诸如此类的，如：
We like such fruits as apples and bananas.
起强调作用，如：
It's such a beautiful day!
This issue was of such importance that we could not afford to ignore it.
Comma+participle" can modify the subject of the previous main clause. This sort of modifier should actually satisfy TWO requirements:
1) it should apply most nearly to the subject of the preceding clause (as you've said); and, even more importantly,
2) it should have one of the following RELATIONSHIPS to that clause:
* immediate consequence
* simultaneous, but lower-priority, action
here, this modifier doesn't have either of these 2 relationships to the main clause, so it's used inappropriately.
when we say "immediate consequence, we mean a consequence that is proximate, immediate, and produced as an essentially unavoidable result of the main action. for instance:
the bullet entered Smith's brain, killing him instantly --> this is an immediate and automatic consequence; if the bullet does this, then smith will be killed.
John scored 90 on the most recent test, raising his overall average by two points --> again, an immediate and automatic consequence; if john gets this score, there will automatically be the stated consequence for his average.
in the problem at hand, drawing new conclusions is not an automatic and essentially unavoidable consequence of amassing the knowledge in question; the researchers must actively go beyond just amassing the knowledge to draw those conclusions.
d) is incorrect because it misuses a "which" construction.
all constructions built on preposition + "which" - such as of which, from which, some of which, with which, etc. - must be used in the same way as "which" itself.
in this case, the "which" is trying to refer to "several posts", which is way too far away from the comma to be acceptable.
if this is really a gmat problem, then the quality of those problems is declining at an alarming rate (or the problem writers were asleep, drunk, etc. when they wrote this problem ... ugh)
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BC很好排除，这里作伴随，但是与主句并无关联，
D，so such that错误
A，修饰是不对的，不能说aviation is new for plane
E，作定语修饰records，合理且正确