主题句：Terrestrial snakes, in particular, exhibit adaptations that aid in circulating blood against the force of gravity.

Such a location requires that blood circulated to the tail of the snake travel a greater distance back to the heart

直接细节题：Because the vertical pressure gradients within the blood vessels are counteracted by similar pressure gradients in the surrounding water, the distribution of blood throughout the body of sea snakes remains about the same regardless of their orientation in space, provided they remain in the ocean.

choice B直接概括了P2的中心思想：The problem confronting terrestrial snakes is best illustrated by what happens to sea snakes when removed from their supportive medium. 陆蛇所面对的问题可以通过当水蛇离开支持媒介面对的来解释
choice C:
生物体对于它所在环境某一个特征的适应性的有效性，只能通过检验其他物种对于一个不同环境的相似特征的适应性的有效性。1）only过于绝对 2）全文没有提到不同环境之间的相似特征（陆地、海洋是完全不同的环境，之间没有相似性）

try to do sth.设法做某事；
try doing sth.试图做某事；
区别是：try to do侧重努力，为了达到目的而努力。
try doing 只是一种新的尝试，不带明显的目的性。

对于有一些表示“出现、就位、形成”的动词，在不会造成歧义的情况下，可以放在被修饰的名词与定语从句之间，以避免动词在长长的修饰成分之后出现，造成了动词距离主语过远的awkwardness. 因此，这题which并没有真的 指代句子 ，而是仍然指代名词（修饰名词）！

这个题目选择B的原因是因为A和C在比较上都有硬伤。比如C吧，应该写成：
wild animals' total fat is less than that of livestock.
这样才是一个正确的表达方式。

E错在if intend..变成状语修饰undergo, 但句义应该是修饰drug.

1. 固定搭配：ability to do sth.有能力做某事；ability of sth./sb. 某某某的能力。
2. Be subject to sth：If someone or something is subject to something, especially something bad, it is possible or likely that they will be affected by it. 其中subject是形容词。
E. the range用了定冠词，可是前面并没有提到过该range，因此定冠词使用错误

A. 比较双方不对等：HC和its return

1. capability to do；GMAT认为capability of X-ing/in X-ing是wordy/awkward的。
2. ability：sb's ability to do sth或ability of sb/sth to do sth
3. capability in doing错，此处in dealing有做状语修饰整个从句的歧义，变为Sulfur dioxide在dealing with的时候减少了respiratory system的能力，而不是原义想要表达的，减少了respiratory system的deal with…的能力；capability如果后面要加in doing,最好紧跟capability，避免歧义

But for N, S + should/would/cold/might + V / (have Vpp.) 若不是N, S应该….
= If it were not / (had not been) for N
= Were it not for N / (Had it not been for N)
= Without N（介词只有without可表虚拟语气）

In fact, in 1970 the SBA explicitly stated that their main goal was to increase the number of minority-owned businesses
定位定错了

price是charge的直接对象（charge a price），所以不需要再加介词，直接that即可；charge at a price是错的，sell sth. at a price倒是可以的(另外price出现在at后面常表示代价)

At the time, minorities constituted seventeen percent of the nation's population, but only four percent of the nation's self-employed.
gap在于少数民族占全国的17%，但是只有全国的创业者的4%

A中的意思变成了 欧洲人1992年到达
B的主语是investment
DE的主语是initiation

demand表示要求的时候只能用虚拟语气
only的位置同时影响到句子的意思

农场和鸟做对比，没想到。农场和鸟都在vanishing

划线部分身后的now drawing是伴随状语，本选项在语法上是没有错误的。但是，依据图形背景原则，相对于“下结论”来说，“积攒知识”的持续时间必然更长，其是“下结论”这个事件的背景。因此，draw应为主句，amass应为从句（伴随状语）。

amass积聚

They conclude that the postwar demise of this vital alliance constituted a lost opportunity for the civil rights movement that followed the war.

demise 终结，，e选项，continuation继续。若继续将会受益