or前后是两句话，两个whether的问题，whether提供的两个选择不会是两个句子呀。or后面省略it's unclear，whether为是否if为如果不冲突，可以放在一句话里

另外注意区分so ... as to ...和so ... to ...
so ... as to ...是一种平行结构。
如：
Major economic shifts are so gradual as to be indistinguishable.
are gradual 和 be indistinguishable平行

而 so ... to ...表示目的，to 后面加动词（包括被动式）
这种情况下 so ... to ...本身具有“太难去做……”的意思，本身就是否定，所以按照上面的语义不需要加否定
如：
Major economic shifts are to gradual to be distinguished.

B so ... so that... 表述错误，应该是 so ... that...
C unable 发出动作应该是人
D adj + (not) to...后面应该加动词表示目的，可以这样表达：Major economic shifts are gradual enough not to be distinguished. 这里的adj是gradual， enough 不是固定搭配表示，实际是 adj后的副词，这样是OK的
E so that 表示主观能动，题目中的economic shift 到 发现 实际是一种客观现象/状态，一般so that 我们这样使用：I got up early so that I could get there on time.

定位——since the process provides a source of novel genes and a mechanism by which a location can be repopulated should the fish there disappear.

2） 25/125=1/5
25=5² 125=5³

在BD中纠结，发现D last是一般现在时，could是过去时，没有特别表示时间的词不能跳时态。

注意选项 C between secondary schools and the workplace never evolved in the United States as
C比对的是in the United States和in most other developed countries
而E as they did，比对的是evolve与否这个动作本身。

MMMMARK

在这道题目中 as many as ， 是把people和 后面的 people who are enrolled in 做比较， 但是为什么可以省略这么多成分

A选项：他可能卖出去4000租出去4001，加起来也就8000，不能证明due almost entirely to the February 1994 opening of Videorama
E选项：他虽然只卖出去4000，但买家会把这些影碟租出去，更少人去Centerville租碟，可证明due almost entirely to

我选A 但是没法用新开的V来完全解释问题

Aramaic script是复数 我晕了 选了D

The 1850 census initiated the collection of specific information about each individual in a household. 可是这句话没有提到除去首脑啊

题中有两组平行：Unlike，and。不要先入为主地判断平行对象是叶子还是植物，而要看两组平行是否都成立。

D选项， making provision for the removal of the government of the United States to the new federal city, Washington, D.C 为什么不能做后一句establish 的伴随状语

第五题的第五个选项是不是需要一个an在understanding之前啊

E主谓不一致啊！仔细看题！

mine和produce之间存在逻辑关系，并非并列！

在require, demand 等表“建议,命令”意义的词（无论动词还是名词）之后的that 从句,要求用虚拟语气动词,即动词原形,不加should

waters水域，可以用where! 没看到A选析最后的they，不能指代与前文they不同的对象

(1) x = 12u, where u is an integer --> x=12ux=12u --> 12u=8y+1212u=8y+12 --> 3(u−1)=2y3(u−1)=2y --> the only thing we know from this is that 3 is a factor of y. Is it GCD of x and y? Not clear: if x=36x=36, then y=3y=3 and GCD(x,y)=3 GCD(x,y)=3
but if x=60x=60, then y=6y=6 and GCD(x,y)=6 --> two different answers. Not sufficient.

(2) y = 12z, where z is an integer --> y=12z --> x=8∗12z+12 --> x=12(8z+1).
So, we have y=12z and x=12(8z+1). Now, as z and 8z+1 do not share any common factor but 1 (8z and 8z+1 are consecutive integers and consecutive integers do not share any common factor 1. As 8z has all factors of z then z and 8z+1 also do not share any common factor but 1).
Thus, 12 must be GCD of x and y. Sufficient.

from gmatclub

CD的差别在于不定式和从句，promote blood clotting应该作定语修饰substance，因为thromboxane是一种substance对于是否promote没有直接决定关系，从后面平行的which prevents clotting也可以看出来，作定语修饰prostacyclin