because of 不能跟在be后面，必须跟着一个normal verb；He do it because of money.

when clause的条件状语从句和rather than应该为一个整体

Prescriptions are the cornerstone of a successful on-line drugstore, [just] as prescriptions are the cornerstone of traditional pharmacies.
Prescriptions are the cornerstone of a successful on-line drugstore, [just] as (this) is the case for traditional pharmacies.
As is the case with traditional pharmacies, prescriptions are the cornerstone of a successful on-line drugstore

is the case和do so一样，可以指代一件事情。不能说as with the case of sth，不能说As the case with sth is，语言习惯里，case指代前面提到过的事情时，不能做主语，R：as…as was the case in 1997，W：as…as the case was 1997，除非case是个名词，如：a court case。
As is the case with sth不需要精确的相关和平行，不需要像like/unlike一样，主句主语是sth的类比对象，如：As was the case in post-world-war-i germany, hyperinflation has been causing general unrest and panic throughout country x.

本题的关键是理解题意 总共可以的组合有8*7*6=336个 总共有330名员工 所以多余6个

ingest 咽下，吃下，吸取 ；和digest消化是两个意思

比率只能用百分比，不能用half

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
B: 主干 a tripling was due to X, in addition to Y 改变了意思。在choice a中用and连接两个原因状语说明两个原因的权重是一样的，in addition to的结构中说明Y的重要性低一些

为什么to allow不是宾补

more than three times as many 【independent institutions of higher education charge tuition and fees of under $8,000 a year 】as 【 ( independent institutions of higher education) charge over $16,000】.

目的状语在这里修饰的是系动词is？目的状语的主语是不是主句主语啊？

作为 制造、生产；产量 是不可数 作为 推出的作品（尤指戏剧、影片等） 是可数；harvest：收获，产量 the quantity of a natural product gathered in a single season
the salmon harvest

结论：因果关系

数字没有办法办法自己比，所以compares错误，只能用compared，这个被动态，数字被比较

“having ”为伴随状语，主语为就近句子的主语，但是gone unregulated只能是污染物

phenomena为复数

a number of这种表示数量的词（ hundreds of/）的核心词是后面的名词，但是“the number of ” “the proportion of”为xx数量，所以以number和数量为主

找到最直接的导致环境污染的问题，就是增加“an increase”只有增加使用才可以导致环境问题，肥料本身和使用都不行，因为都不能达到量大，然后到达环境污染

这里的hints 的定语核心词是oil supplies

为什么that 是表语从句？主谓宾后面还能接表语嘛？也不可能是宾补，因为宾补不能是个句子。