3.20逻辑答案

韩小宁

1、Parasitic wasps lay their eggs directly into the eggs of various host insects in exactly the right numbers for any suitable size of host egg. If they laid too many eggs in a host egg, the developing wasp larvae would compete with each other to the death for nutrients and space. If too few eggs were laid, portions of the host egg would decay, killing the wasp larvae.

Which of the following conclusions can properly be drawn from the information above?

A The size of the smallest host egg that a wasp could theoretically parasitize can be determined from the wasp's egg-laying behavior.  .
B Host insects lack any effective defenses against the form of predation practiced by parasitic wasps.  .
C Parasitic wasps learn from experience how many eggs to lay into the eggs of different host species.  .
D Failure to lay enough eggs would lead to the death of the developing wasp larvae more quickly than would laying too many eggs.  .
E Parasitic wasps use visual clues to calculate the size of a host egg.


1、正确答案：A
2、原文逻辑：前提：一种昆虫产卵的行为特征是，往合适的任意尺寸体积的宿主卵里面下相应的合适的数量的蛋。
          结论：如果这种生物产卵数量太多，则这些卵相互竞争食物而死；如果产卵数量太少，则原寄主的蛋中的营养成分腐烂分解，杀死这种生物的卵。
3、归纳题：哪种结论可以从上述信息中得出？
4、选项分析：A.这种生物寄生的最小的蛋是由这种生物的下蛋习性决定的。
          B 寄主昆虫对于这种生物没有有效的防护能力
          C这种生物通过经验来得出在不同物种的寄主中的下蛋数量。
          D下蛋数量少比下单数量多引发的这种生物的卵死亡更快
          E这种生物用眼睛判断寄主蛋的大小
5、解题思路：原文中其实就是想说明这种昆虫的下蛋习性，下蛋数量很合适，不能多也不能少，因此BBE肯定能排除，无关信息。然后C选项很容易误选，但是原文中没有说明是根据物种，而是说根据蛋的大小，因此选A。

2、The total market value of real estate in Altonville has steadily declined over the past four years. This decline has meant that the overall figure on which the city's property tax is based-the assessed value of that real estate-has also declined. The percentage of assessed value that was paid as property taxes to the city, however, did not change from year to year during this period.

The information above most strongly supports which of the following?

A The percentage of Altonville's yearly revenue that comes from money collected in property taxes did not change over the past four years.  .
B The percentage of Altonville's yearly revenue that comes from money collected in property taxes has declined steadily over the past four years.  .
C The amount of revenue that Altonville collected from property taxes was lower last year than it was four years ago.  .
D During the past four years, Altonville officials increased tax rates on other sources of revenue such as retail sales and business profits.  .
E Altonville will soon require property owners to pay a higher percentage of the assessed value of their property as property tax.

1、正确答案：C
2、原文逻辑：前提：A市值下降，同时所交财产税的基数也下降
结论：财产税比例没变
3、选项分析：A选项说A城市这四年来财产税的收入占总收入的比例没有改变。B选项说A城市这四年来财产税的收入占总收入的比例下降。C选项去年财产税的收入比前 4年低。D选项说A城市的政府官员提高了其他税种的税率。E选项说A城市将要很快要求财产拥有者交高税率的财产税
4、解题思路：其实这道题并不难，只是需要数学思维。原文其实就是说财产税比例不变，基数下降，因此收上来的财产税少。这与财产税占总税收收入的比例无关，也与其他税种的收入无关。想要保持结论的成立，就直接找出一个选项说明税少了就可以了。因此选C。AB选项说的是财产税占总税收的比例，可能不变也可能减少，甚至可能增加，这取决于总税收和财产税的多少，而不单单是财产税，因此不对。D选项说其他税种，无关。E选项说要提高财产税税率，不符。

3、In tests for pironoma, a serious disease, a false positive result indicates that people have pironoma when, in fact, they do not; a false negative result indicates that people do not have pironoma when, in fact, they do. To detect pironoma most accurately, physicians should use the laboratory test that has the lowest proportion of false positive results.

Which of the following, if true, gives the most support to the recommendation above?

A. The accepted treatment for pironoma does not have damaging side effects.  .
B The laboratory test that has the lowest proportion of false positive results causes the same minor side effects as do the other laboratory tests used to detect pironoma.  .
C In treating pironoma patients, it is essential to begin treatment as early as possible, since even a week of delay can result in loss of life.  .
D The proportion of inconclusive test results is equal for all laboratory tests used to detect pironoma.  .
E All laboratory tests to detect pironoma have the same proportion of false negative results.

1、正确答案: E
2、原文逻辑：前提：检测一种病毒，会出现两种错误情况，一种是positive false没病被测出有病，一种是negative false有病被测出无病。
                        结论：为降低失误率，用实验室的方式测验会降低第一种positive false的出错比例。
3、选项分析：A 接受治疗不会有负面作用。B实验室检测出低的positive false造成的负面影响比其他的实验室方法小。C得这种病的病人要及早治疗。D所有实验室的出的不确定概率是一样的。E所有实验室得出negative false的比例是一样的。
4、解题思路：A说负面作用与原文无关。B选项说的是这种检测方法的负面作用与其他实验室的比较，而不是方法间的比较，无关。C选项更无关。D选项没有说明任何问题。D选项说所有实验室方法得出第二种错误的比例是一样的，因此得出一种错误越少越好。符合结论，选E

4、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.

The argument above requires which of following assumptions?

A During the year following the tax increase, the pretax price of a pack of cigarettes did not increase by as much as it had during the year prior to the tax increase.  .
B The one percent fall in cigarette sales in the year prior to tax increase was due to a smaller tax increase.  .
C The pretax price of a pack of cigarettes gradually decreased throughout the year before and the year after the tax increase.  .
D For the year following the tax increase, the pretax price of a pack of cigarettes was not eight or more cents lower than it had been the previous year.  .
E As the after-tax price of a pack of cigarettes rises, the pretax price also rises.

1、正确答案：D
2、原文逻辑：前提：Year0的Sales下降1%，Year1的1Sales下降10%
Year1中Tax上升了8%
结论想证明税后价格与售价之间的关系。
3、选项分析： After-tax Price=Pretax Price*(1+Tax) 五个选项中只有D表明pretax price不会比加税前低8%，那么after tax price必然就会高于year0的after tax price,导致最终price上升，因此成为销量下降的主要原因。   
         
5、In order to finance road repairs, the highway commission of a certain state is considering a 50 percent increase in the 10-cents-per-mile toll for vehicles using its toll highway. The highway commissioner claims that the toll increase will increase the annual revenue generated by the toll highway by at least 50 percent per year.

Which of the following is an assumption on which the highway commissioner's claim depends?

A The amount of money required annually for road repairs will not increase from its current level.  .
B The total number of trips made on the toll highway per year will not decrease from its current level.  .
C The average length of a trip made on the toll highway will not decrease from its current level.  .
D The number of drivers who consistently avoid the highway tolls by using secondary roads will not increase from its current level.  .
E The total distance traveled by vehicles on the toll highway per year will not decrease from its current level.  

1、正确选项：E
2、原文逻辑：前提：为了给修路筹集资金，这个commission准备在原有的10cents 每mile的基础上加50%。
          结论：增加的费用会给总收入带来50%的增长。
3、假设题
4、选项分析：若想总费用按照per mile的相同比例增长，则需要机动车旅行的总里程数不变。因为total toll= increase toll per mile * total miles如果机动车辆旅行的总距离下降的话，那么就达不到原来预想的结果，所以选E。A选项说总的修路费用不变，B选项说总的旅行数量不变，C选项说旅行的平均长度不变，D选项说为了避开收费而选择其他道路的司机数量不变。


小总结：这次出的题很多都是逻辑与数学相关，做题时需要理清题中的数学变量。