GMAT8月考试的一些答疑 - 2010年8月13日（3）
Scientists have dated sharp-edged flakes of stone found in the fine-grained sediments of a dry riverbed in the Afar region of Ethiopia to between 2.52 and 2.60 million years ago, pushing back by more than 150,000 years the earliest date when it is known that humans made stone tools.
A. when it is known that humans made
B. at which humans are known to have made （答案）
不知date或是age后面接when或at which有没有区别，A错误的原因是因为it没有指代对象吗？
-----------B正确，这是一个结构优化的问题，改成when humans are known就正确了，it在这里不是指代问题，而是它就是这个句子的主语，变得非常啰嗦混乱；时态上说，这里说一个科学事实，不要用过去式，这不正确。 所以，比较来看，B最好。
By merging its two publishing divisions, the company will increase their share of the country’s $21 billion book market from 6 percent to 10 percent, a market ranging from obscure textbooks to mass-market paperbacks.
-----用了两次MARKET，不好，而且从句前面没有明确指明是什么，后面从句就乱了，不正确。
A. from 6 percent to 10 percent its share of the $21 billion book market in the country, which ranges
B. to 10 percent from 6 percent its share of the country’s $21 billion book market, which ranges
答案给的是A，但是which前是country不会指代错误吗？不知B选项错在哪里呢？
-----A读起来是最舒服的，这也是一个GMAT考试的要点，即文章和句子的预感很重要，一般不说to XXX from XXX, 很别扭。In the country作为状语修饰，不影响后面从句的指代是MARKET。
A recent review of pay scales indicates that CEO’s now earn an average of 419 times more pay than blue-collar workers, compared to a ratio of 42 times in 1980
----这句话有问题，是419倍于什么，没有讲，漏了一个工人的“工资”。要加上the pay of 或that of 才行。.
A. that, on average, CEO’s now earn 419 times the pay of blue-collar workers, a ratio that compares to 42 times
---------a ratio这里勉强可以指代前面的419，但是很不清楚，因为句子前面出现的是工人。GMAT考试中和一般英文写作中，很反感这种在一句话里反复不停用指代词语，对比上一道题。
B. that, on average, CEO’s now earn 419 times the pay of blue-collar workers, as compared to 42 times their pay, the ratio
B的句子架构感觉“awkward”，认为A表述的很清楚啊，不知错在哪里？
这个可以，as compared to 就指代前面一整句话的意思，所以后面直接是42 times.
Minivans carry as many as seven passengers and, compared with most sport utility vehicles, cost less, get better gas mileage, allow passengers to get in and out more easily, and have a smoother ride.
A. Minivans carry as many as seven passengers and, compared with most sport utility vehicles, cost less,
B. Minivans, carrying as many as seven passengers, compared with most sport utility vehicles, cost less,
A中carry, cost，get，allow，have是构成平行结构吧，如果是这样的话，平行结构不是要么每部分前面均有and，要么只有最后一个有and，前面不用加，为什么A中compared前面还要加and呢？ 觉得B选项相比之下更好一下啊，不知自己的想法错在哪里？
-------这道题考的就是一个结构和句式的统一，平行结构不是carry, cost，get，allow，have这些动词，而是他们在句子中在carry as many as后都是比较级的说法，cost less, get better, more easily, have a smoother ide, 所以把状语性质的as comapred to单独出来，必须加and，这就正确了。 B也可以，很勉强，因为有两个从句，一个ING一个过去分词开头的从句放在一起，很混乱。