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题库 / Prep2008E1-SC-202
Providing initial evidence that airports are a larger source of pollution than they were once believed to be, environmentalists in Chicago report that the total amount of pollutant emitted annually by vehicles at O'Hare International Airport is twice as much as that which is being emitted annually by all motor vehicles in the Chicago metropolitan area.
as much as that which is being emitted annually by all
as much annually as is emitted by the
as much compared to what is annually emitted by all
that emitted annually by all
that emitted annually compared to the
题目分析：
略。
选项分析：
A选项：is being emitted时态有误。本题的比较对象是“在机场的车辆释放的污染物量”和“市区所有机动车释放的污染物量”，因此，不能说是“在机场的车辆释放的污染物量”和“市区所有机动车正在释放的污染物量”（这样后者肯定少了，因为只是某一时刻的量）。
B选项：副词annually应修饰动词emit，即，每年地释放，而不能修饰much。
C选项：语法有误，as much as是正确的搭配，不能用as much compared to。
D选项：Correct. 本选项在语法和逻辑上均是正确的。twice后面可以直接接名词，也可以加as much as。
E选项：过去分词短语compared to应改为介词by。这是因为，后一个比较对象应是“市区所有机动车释放的污染物量”，即，motor vehicles in the Chicago metropolitan area是emit的逻辑发出者。被动语态规定，be done by A中的A才是do的逻辑主语。
(1) If you say "twice as many", then this construction should be paired with acountable noun. e.g., twice as many dogs --> "dogs" is a countable noun
(2) If you said "twice as much", then this construction should be paired with anuncountable noun. e.g., twice as much water --> "water" is an uncountable noun
1. twice可以直接加名词，twice（as much as）sth；
2. that 指代pollution。
D： that指代整个amount of pollutant
that指代pollution 注意构成平行
that指代pollution，构成平行
注意is being时态问题
i think the combination of "amount" and "as much as" would be tagged as redundant and therefore wrong.
i am not 100% on this, as the gmat's usage preferences are rather slippery at times, but there's no doubt that this suggestion is inferior to the version without "as much as".
shorter versions:
amount X is twice as much as amount Y --> inferior, and possibly even wrong (redundant)
amount X is twice amount Y --> undoubtedly better
just look at the parallel structures side-by-side, and notice which parts match up to which other parts.
/the total amount of pollutant/ emitted annually by vehicles at the O'hare International airport
is twice
/that /emitted annually by all...
Ron的解释
A选项中的being： "being" doesn't make sense because it's not parallel to anything in the earlier part of the construction.
B：the real problem is that "is" has no parallel in the first part of the comparison - i.e., the first part doesn't say "is emitted" or "are emitted" - and so the comparison is wrong.
感恩
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我的解释：
①原句中强调了all，如果省去的话会改变原句的意思，所以排除BE
②A中as much as that which ...(that which 很wordy）排除A
③as much + compared to 错误
选C
非数字物体通常用double(twice) as much as或double(twice) as many as,当数字进行比较时直接用twice或double
note that you have "compared to motor vehicles...", which implies that we are making a direct comparison between pollutants and motor vehicles (rather than between pollutants and pollutants, as in the correct answer. that's nonparallel and thus wrong.
"that" stands for" the total amount of pollutant "
the real problem is that "is" has no parallel in the first part of the comparison - i.e., the first part doesn't say "is emitted" or "are emitted" - and so the comparison is wrong.
twice more than 比...多两倍（三倍）
twice as much as 是...的两倍
twice＋数字概念，that指代total amount of pollutant，本题适用，则(D)正确
twice as many/much as＋非数字概念，本题不适用
比较也要考虑时态问题 要能比
记得之前有道题提到过非数字物体通常用double(twice) as much as或double(twice) as many as,当数字进行比较时直接用twice或double,这道题可不可以直接排除掉ABC呢？
同问！
可以。
同答。
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twice＋数字概念，that指代total amount of pollutant，本题适用，则(D)正确
twice as many/much as＋非数字概念，本题不适用
B选项，如果把annually的位置调整，比如as much as is emitted annually by...是不是也不对？因为is？
我认为是对的，因为is前面相当于省略了pollutant
不对，缺少比较对象， the amount of pollutant,(that)
感觉这题可以直接用平行做，因为D选项是绝对平行的，所以肯定比其他好
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选项A is being 错误，as可以做比较从句的主语，变为as much as is emitted annually即便如此也不如twice amount Y 简洁
选项B annually位置错误
选项C 搭配不当
选项E compared to 多余