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】.

There are as many schools charging under $8,000 a year as those charging over $16,000.
As many schools charge under $8,000 a year as charge over $16,000.

我开始也觉得应该是比较机构，所以觉得E好一点。现在看来E选项as后面的和前面不对称
as many institutions charging under 8000 as those charging over 16000 (比较主体是institutions)
或者
as many institutions charge under 8000 as (institutions) charge over 16000 （比较主体是charge...）

亲，这里比较的就是机构数量啦，只是省略了“independent institutions of higher education ”。
可以参考shirley17的回答：
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】

由于本题已经讲过了more than three times as many，所以划线部分必须以as开头。排除(A)(B)(C)。这道题目的意思是：收取学费少于8000每年的高等教育机构是超过三倍于收取超过16000每年的学费的机构的。由于as many as中间是一个行为，即，independent institutions of higher education charge tuition and fees，因此本题的对比对象应为两个收费行为，as身后应该用动词charge over $16,000，不能比较机构数(those charging over $16,000)。

倍数的比较：
three times as much as; three times more than; three times B
as many independent institutions charge tuition and fees of under $8,000 a year as those charging over $16,000，这个结构的意思是as被后置，还原成 as many independent institutions as those charging over $16,000 charge tuition and fees of under $8,000 a year，二者一起charge 8000，错误

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】.

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】.

as many institution charge.... as (those) charge suggesting the behavior is compared
it also could be:
as many institution charging... as those charging suggesting the institution is compared

本题考查“比较”的知识点。首先，表示比较时，as…as…和more…than…均可以。例如，我们可以说：three times as many as，也可以说：three times more than（当然，这两者表示倍数不同）。但是，as必须和as搭配，more必须和than搭配，不能混搭。由于本题已经讲过了【more than three times】 as many，所以划线部分必须以as开头
（有比较级(more)就有than没有错，但注意本题前面已经说了more than！！）

看了这道题目半天，其实排出ABC后... 这个句子是缺乏一个动词的，按照这种逻辑其实也可以容易地排除 e

(D) "Charge X amount" is perfectly parallel to "charge Y amount" in the first half.

(E) "Those charging" has no counterpart in the first half.

本题的对比对象应为两个收费行为。

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】.
不要想当然，有关比较的题把所有成分补全
比较的是institutions charge 8000和institutions charge 16000
E. 应该改成There are as many schools charging under $8,000 a year as those charging over $16,000.才对

E: 没有可以平行于those charging的结构，这里是比较charge的内容

因此本题的对比对象应为两个收费行为

注意！ron神曾经说过more than 和as as不会出现在一个句子里面，是要看功能的！这里的more than 和as as并不是在一个成分结构上面！

More people walk than drive in New York.比较的是walk和drive，不能改成than those driving，those driving没有平行对象，除非改成There are more people walking than those driving.
more than three times as many institutions charge 8000 as charge 16000，比较对象是charge 8000和charge 16000，改成as those charging会使 those charging找不到平行对象。

as必须和as搭配，as后对象必须平行

还原以后看省略