语文分册CR29，求助求助求助！！！！！

宝爱一

Pro-Tect Insurance Company has recently been paying out more on car-theft claims than it expected. Cars with special antitheft devices or alarm systems are much less likely to be stolen than are other cars. Consequently Pro-Tect, as part of an effort to reduce its annual payouts, will offer a discount to holders of car-theft policies if their cars have antitheft devices or alarm systems.

which of the following, if true, probides the strongest indication that the plan is likely to achieve its goal?
A: The decrease in the risk of car theft conferred by having a car alarm is greatest when only a few cars have such alarms.
B: The number of policyholders who have filed a claim in the past year is higher for Pro-Tect than for other insurance companies.
C: In one or two years, the discount that Pro-Tect is offering will amount to more than the cost of buying certain highly effective antitheft devices.
D: Currently, Pro-Tect cannot legally raise the premiums it charges for a given amount of insurance against car theft.
E: The amount Pro-Tect has been paying out on car-theft claims has been greater for some models of car than for others.

答案是C,  我选了A。。。。看后面的解释发现我所理解的A和解释说的A完全相反！！。。。我现在已经看不懂A在讲什么了。。。我选的时候以为：当一些车有这种警报器的情况下，有警报的车被偷的风险的减少是最大的。。。难道不是说警报器减少了车辆被偷么。。。为什么A的官方解释是说：If having more cars equipped with car alarms reduces those alarms' effectivity in preventing thefts....

PS：CD的搜索功能彻底不能用了是么？~~~~(>_<)~~~~

宝爱一

upupupupupupupup

lacedaemonian

你对答案A的理解是没有问题的：当仅有一些车有警报器的时候，车因为有警报器而被偷的风险减少的最大。这个答案是个明显的干扰项，说的很饶舌。但是这个选项很容易排除，因为它说的问题，和本题的逻辑根本不相干。

jannis

想象一个开口向下的二次函数.横轴是装备报警器车的数量，纵轴是decrease in the risk.
这样的车越多，decrease in the risk就越小，那么这个公司的计划就越无用