同义转换
continuously test the market---------------- and use the results to secure concessions from existing suppliers
Obtain bids from other providers of health care benefits--------in order to be in a position to negotiate a better deal with the current provider.

实际上可以排除法做出来。可能选错的D：when not directly related to production, corporations often favor “supplier partnerships. 并不能推出when directly related to production, corporations do not favor SP(很典型的伪是非情景）
B选项可以看比较的是in a competitive-bidding situation--即purchases have right
supplier partnerships”--(arrangements in which the purchaser forgoes the right to pursue alternative suppliers)-- purchasers do not have right

错误原因：不相信答案....实际上D和E都有很明显的错误：D中的revitalize 和create是有区别的； 而且hope to有目的的意思，文中并没有说他的目标是E的顺序颠倒。

B的含义是：change a number of prevailing attitudes in order for his mass movement to find a foothold in the United States。 因为scholar 认为是MG create the consciousness, 所以这些学者默认consciousness是之前没有的。（在后面一句也提到了consciousness of identity, strength, and sense of history that already existed in the African American community来反驳学者），所以学者的argument是基于consciousness of identity, strength, and sense of history not existed in AAC。so there's sth need to be built for the movement.

they指代 linking xxx 这件事不奇异么，they不应该是复数指代么。

错误原因：引入了extra assumption 错选E。原文的意思是任期长的C 带来独特的knowleged, 所以更易acquire post-acquisition success. 但并没有说任期短就会导致acq失败

错误原因：选项理解错误/定位错误，D理解成从parasite infection recover的能力（但实际还是错误）
题目已经给出定位了： bright carotenoidbased coloration---when choosing mates, females prefer males with brighter carotenoid-based coloration
同时也可从最后一句看出：whereas males that are genetically resistant will use fewer carotenoids for fighting disease and will advertise this by using the pigments for flashy display instead.---即表示他们genetically more healthy,即fitness

做对了，但是需要强化伴随状语是修饰谓语动词这一概念

"whether or not" is almost always considered redundant on GMAT.

谁能准确的说一下这句话里面为什么要用if and when，这俩从意思上说有什么区别么？不是都表示“当”的意思么？
the hunting season ends if and when hunting has reduced the population by five percent, according to official estimates.

B is wrong because "is" is redundant

这个B推理的也太多了吧，一般来说这样不是都不ok么。。。虽然可能只有B可以推出，未来产生变化的时候会怎样。。。

错误原因：想太多...
”services” provided by ecological systems and have economic value-indeed. B选项错误：water purifying plant不是naturel provided
另外可以直接参考原文中Tourists visiting wildlife preserves（即C选项）,; undisturbed forests and wetlands regulate water runoff and act as water-purifying systems,

文章框架：1.a study test the impact. for high price, impact-positive; for low price, impact-negative (here we have a disadvantage)
2.mainly focus on the benefit of a SG

错选原因：没有vet in the choice answer. 首先C选项：examine the conventional wisdom regarding the effect of service-quality guarantees in the restaurant industry。表示重点是评估这个wisdom, a wisdom regarding the SQG in restaurant industry. 文中唯一一处出现一个convention wisdom的是关于electric industry的，错误。E选项：consider the impact that service-quality guarantees can have on the service provided by a restauran。 应该是impact on customer perception,错误。

A. it指代budget 意思不对

CE可以认为也错在逗号and上么？明显只用and连接更合理，表示递进和继续发生。

不是刚说that有没有都行么？为啥在解释E的时候又说that应该在some time in the past之前呢？

有cost for这种说法么？我是觉得这里怪怪的，所以DE里面选了E。

C的真正错误在于which在这里不适合，一定要用that引导这个从句