我会在A和D中选。老师分析的对，D选项是在跟自己比，跟此题的意思不一致。A的说法中above-average，是在跟别人比。如果这么思考，那么不应该选择D。

AB选项so..as to 和so... that并没有什么问题，但是A选项后面没有B选项的of表达的简介明了，GMAT语法题在语法正确的前提下还有一个要求就是要简洁明了。

C, 未提及是否尤其容易被judge判无效 (暂且这么理解？）

why C is incorrect? I kept both C and E, and ultimately choose C

其实本质是一个CR题，问reason的

D选项错误原因：
原文有提到population增加，但是population增加并不是导致proportion of verdicts in favor of pantentees began to increase in the 1830s 的真正原因（试想：方法论不改变，最终结果不会有本质的变化），population的增加只是一个事实而不是原因，population的增加是被（原文提到的后面那句才是根本原因，找C的原因--> caused by b--->caused by A, then A is the real reason）

这题正确答案是B。
https://www.manhattanprep.com/gmat/forums/tiger-beetles-are-such-fast-runners-cr-t3238.html

定位原文是often shifted positions along the continuum

原文是direct, tangible benefits， 但A只说了tangibility of benefits。但是C项很宽泛，就cover了原文的意思

C选项 this也错了

暂时把这个形式背下来吧，不知道A和E有啥区别，为何A对。

take business from是在抢生意呀。

好复杂的关系，这个反对那个支持，这个机构那个机构的，啊，好晕

我看了一眼曼哈顿这个粗体字画错了。。。没看到正确版本。。。随便了

but, upon reflection, it makes sense: if the purpose of the argument is to counter another argument, then some sort of attribution must be given for that argument (even if that attribution is vague, e.g., "some have said..."). by contrast, there is no need to quote an authority for an argument that the passage itself is making, especially given the rather severe constraints on the size of the passage.

these questions are always somewhat difficult, but here is a hint that will help you figure out the structure in this case: * the passage starts out by quoting someone else (i.e., "a prominent investor"). if a passage starts out by quoting a different person, then the purpose is almost always ultimately to contradict that person's argument. this is a purely empirical argument from looking at many of the gmat questions,

in this case:in burton's case the increased inventory of finished products does not indicate blah blah blah; THEREFORE, the investor's claim is not justified"--> this makes sense. the investor's claim is not justified; THEREFORE, in burton's case the increased inventory of finished products does not indicate blah blah blah"--> this doesn't make sense. hence, "the investor's claim is not justified" is the conclusion.

Ron's explanation； (d) is incorrect. if you are unsure about which of two statements is the ultimate conclusion, then use the "therefore test":* try "X; therefore, Y" * try "Y; therefore, X" whichever of these make sense is correct, and whatever follows "therefore" is the conclusion.

think about the percentage in the first sentence of the argument. mathematically, that's 100% x (people who moved to florida)/(people who moved between any two states) statement (d) says that the denominator of this percentage has increased markedly. it should be clear that this statement is not insignificant.

Ron's explanation: do note, however, that the correct answer to strengthen/weaken choices must be outside the scope of the original argument!
you can't just repeat information from within the argument; it's impossible to strengthen or weaken an argument with things that are already in it. in such problems, just watch out for passages and choices that confuse percentages with absolute numbers; this type of confusion is a rather common theme in cr.