下面的题目均选自GMAT逻辑PREP中的例题，并且按照开篇所讲的解题心得和解题步骤来进行，大家可以通过下面的例题好好体会方法。
一、CR解题心得
第一步 读懂句子、找逻辑链(甚至翻译都可以)
第二步 选择答案
第三步 在不看正确答案的前提下，对每个选项进行分析，找每个选项的逻辑链
第四部 对照正确答案
第五部 总结，按照某些牛人的总结来进行分类
心得：逻辑的本质是阅读
二、CR解题步骤：
1， 读懂句子寻找逻辑链
2， 预判答案
3， 看选项，不在逻辑链上的，没建立联系的、出现新概念的、完全无关的全部排出，至少已经可以排除掉3个选项了
4， 他因削弱结论=》让他因成为假设以使结论成立。
5， 推理有flaw，让flaw消失，即让flaw成立即可使结论成立
Practice Test #1 Critical Reasoning
73. (25075-!-item-!-188;#058&001412)
Most of Western music since the Renaissance has been based on a seven-note scale known as the diatonic scale, but when did the scale originate? A fragment of a bone flute excavated at a Neanderthal campsite has four holes, which are spaced in exactly the right way for playing the third through sixth notes of a diatonic scale. The entire flute must surely have had more holes, and the flute was made from a bone that was long enough for these additional holes to have allowed a complete diatonic scale to be played. Therefore, the Neanderthals who made the flute probably used a diatonic musical scale.
In the argument given, the two portions in boldface play which of the following roles?
A. The first introduces evidence to support the main conclusion of the argument; the second is the main conclusion stated in the argument.
B. The first introduces evidence to support the main conclusion of the argument; the second presents a position to which the argument is opposed.
C. The first describes a discovery as undermining the position against which the argument as a whole is directed; the second states the main conclusion of the argument.
D. The first introduces the phenomenon that the argument as a whole seeks to explain; the second presents a position to which the argument is opposed.
E. The first introduces the phenomenon that the argument as a whole seeks to explain; the second gives a reason to rule out one possible explanation.
74. (29534-!-item-!-188;#058&004138)
In a certain wildlife park, park rangers are able to track the movements of many rhinoceroses because those animals wear radio collars. When, as often happens, a collar slips off, it is put back on. Putting a collar on a rhinoceros involves immobilizing the animal by shooting it with a tranquilizer dart. Female rhinoceroses that have been frequently recollared have significantly lower fertility rates than uncollared females. Probably, therefore, some substance in the tranquilizer inhibits fertility.
In evaluating the argument, it would be most useful to determine which of the following?
A. Whether there are more collared female rhinoceroses than uncollared female rhinoceroses in the park
B. How the tranquilizer that is used for immobilizing rhinoceroses differs, if at all, from tranquilizers used in working with other large mammals
C. How often park rangers need to use tranquilizer darts to immobilize rhinoceroses for reasons other than attaching radio collars
D. Whether male rhinoceroses in the wildlife park lose their collars any more often than the park’s female rhinoceroses do
E. Whether radio collars are the only practical means that park rangers have for tracking the movements of rhinoceroses in the park
是麻醉枪导致母犀牛生育率低，问评价。 C选项再说这种麻醉枪的使用率是多高，如果高的话就是它导致犀牛不育，如果不高的话，可能就是别的原因
逻辑链：
在公园给犀牛栓铃铛、铃铛掉、补铃铛要打镇静剂、掉铃铛多的打镇静剂多、结果发现打的多的生育率低，问评价
简单逻辑链：镇静剂导致生育率低
其他选项都不在逻辑链上
75. (33198-!-item-!-188;#058&007254)
In the year following an eight-cent increase in the federal tax on a pack of cigarettes, sales of cigarettes fell ten percent. In contrast, in the year prior to the tax increase, sales had fallen one percent. The volume of cigarette sales is therefore strongly related to the after-tax price of a pack of cigarettes.
Which of the following, if true, would most strengthen the argument above?
A. During the second year after the tax increase, cigarette sales increased by a significant amount. 无关
B. The information available to consumers on the health risks of smoking remained largely unchanged in the period before and after the tax increase. 加强，在其他变量前提没变的情况下可以得出此变量导致结果
C. Most consumers were unaware that the tax on cigarettes was going to increase. 削弱。不知道税要升、该买的还继续买，断桥：因为税上升、知道要上升、不买了、销售下降的逻辑链
D. During the year following the cigarette tax increase, many consumers had less income, in inflation-adjusted dollars, than they had had in the previous year.同理，削弱
E. During the year after the tax increase, there was a greater variety of cigarettes on the market than there had been during the previous year. 无关
逻辑链：
烟税上升前，销售下降1%，上升后，销售下降10%，说明销售与税上升有关(到这里就应该看，为什么忽然排斥他因?这是flaw。要加强原文argument的，就要将flaw进行补救;要是削弱，那就是放大flaw、点名flaw)。
增加了8分钱税，但是香烟销售下降10%，对比没增税之前只下降1%，说明征税有用。问加强?B选项再说关于香烟有害身体健康对于那些经常吸烟的人的影响没变化，在征税之后，言下之意应该是说吸烟者不是因为吸烟有害身体健康才减少吸烟，而是确实因为税收。
76. (28782-!-item-!-188;#058&003417)
Which of the following most logically completes the argument?
According to experts on shopping behavior, more shoppers would shop at Jerrod’s department store if they were offered the convenience of shopping carts. In fact, even if the amount spent by these additional customers only just covered the cost of providing the carts, providing carts would still probably increase Jerrod’s profits, since _______.
A. the layout of Jerrod’s is open enough to accommodate shopping carts comfortably
B. several department stores that compete with Jerrod’s have begun to make shopping carts available to their customers
C. there are some potential customers who would not be enticed to shop at Jerrod’s by the availability of shopping carts
D. stores that make shopping carts available to customers usually have to hire people to retrieve them from parking areas
E. a customer with a shopping cart buys more, on average, than a customer without a cart
加购物框，会有更多人来、即使多来的人只能抵消掉加购物框的成本、最后也还是赚钱的
增加购物框=赚钱
说增加推车可以增加顾客，事实上即使增加这些车的成本刚刚够和因此带来的多的销售额，那也要加车，问补充。 E选项在说增加车之后每个消费者买得比以前多了，所以侧面说增加了销售额。
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