A/C：
A，differences in how the two ears hear a given sound，how引导名词性从句，句子核心是：“两只耳朵如何听一个声音的差异”
C，differences in the two ears hearing a given sound，句子核心是：“两个耳朵的差异”，“听一个声音”作ears的定语，置于differences从句的第二层，没有A的表达效果好。

错选了E，认为是一种伴随，但是伴随状语强调的是一种自然而然的因果，很显然“事实上这个数字可以做温度计”显然不是一个自然而然的结果！！！

as seen过去分词作伴随状语，逻辑主语是主句主语the rate at which trees grow，这点C/E都是合理的
C，on earth作主句状语，修饰谓语动词is believed，意为在地球上，树木的生长速率被认为是最可靠的迹象之一（那么在月球上就不这么认为了？）；E，on earth作indications的定语，是地球上最可靠的指标之一，ok

同位语，同为名词或句子，既不是定语也不是状语

后四个选项都不对，尤其E，没说他们比comet慢啊！不要脑补。

C，most of them at least as large as Jupiter做80 massive planets的同位语，circling做定语。
some of them/some除了引导完整句外，也可以用于独立结构（同位语，非从句）
eg.:
This model explains all known subatomic particles, some discovered only recently.
When at university, Tom did many travels, some of them places of interest.

名词+分词/不定式/形容词/副词/介宾短语/名词属于独立主格做状语，同时也有可能是同位语，作定语或状语

The researcher found, as expected, that the computer-model stream broadened with time. 时间越长越宽！

Studies have demonstrated that only about 10 percent of buyers for many types of frequently purchased consumer goods are 100 percent loyal to a particular brand over a one-year period. Moreover, 100-percent-loyal buyers tend to be light buyers of the product or service.

The reasons for this behavior are fairly straightforward: people buy different brands for different occasions or for variety, or a brand may be the only one in stock or may offer better value because of a special deal.

because the costs of serving highly loyal customers are lower, and because such loyal customers are less price sensitive than other customers.

80/20" principle, which states that about 80 percent of revenue typically comes from only about 20 percent of customers

B。High labor rates are not necessarily inconsistent with the goals of companies that want to reduce costs.
错选了D，但是根据原文定位第五行可以排除D。一定要看清选项。

纯纯的眼神不好看错了，D确认一个支持在管理者中间普遍存在的观点的来源！！！
E.表明一个可以让一个特定的myth小时的方式途径。themyth that labor rates and labor costs are equivalent is supported by business journalists，who frequently confound the two.

PREP07 Test 1 & GWD，弃！
as compared，当与某物比较时热earn 419倍，这样的表达非常奇怪

A，earn more pay than blue-collar workers可以看成是earn more pay than blue-collar workers do,因为根据语意workers只能跟CEOS平行，workers earn pay，不能是earn workers
【the real problems with choice a: 】 - 'the ratio of 42 times' is redundant; it'd be good enough just to say '42 times'.

C.解决了顾客忠诚项目支持者提出的观点？意思是解释➕反驳了观点？？？

当时在A和D之间纠结，最后看到in sum就选了A！仔细想想可能D更合适，又提出了新的evidence。作者不是单纯的总结上文的arguments，而是自己还提出了观点支持N。一定不能读丢，每一句都想想和上一句的关系！！！

could是过去式

where 只能修饰实体的地点，如area, site, country, society；
对于metaphorical place时，如condition, situation, case, circumstances, arrangement用 in which，不用where；
修饰在某物，如I have a book/company in which……等，用in which，不用where

in societies where little salt is consumed,如果改成in which，则是in societies in which，很奇怪，用where更优

A is among the most famous works, 英语常用句型，表示某物是最著名的作品之一。