请教LSAT-Set2-SecII-16

gu946

The advanced technology of ski boots and bindings has brought a dramatic drop in the incidence of injuries that occur on the slopes of ski resorts: from 9 injuries per 1,000 skiers in 1950 to 3 in 1980. As a result, the remainder of ski-related injuries, which includes all injuries occurring on the premises of a ski resort but not on the slopes, rose from 10 percent of all ski-related injuries in 1950 to 25 percent in 1980. The incidence of these injuries, including accidents such as falling down steps, increases with the amount of alcohol consumed per skier.

16. Which one of the following can be properly inferred from the passage?
(A) As the number of ski injuries that occur on the slopes decreases, the number of injuries that occur on the premises of ski resorts increases.
(B) The amount of alcohol consumed per skier increased between 1950 and 1980.
(C) The technology of ski boots and bindings affects the incidence of each type of ski-related injury.
(D) If the technology of ski boots and bindings continues to advance, the incidence of ski-related injuries will continue to decline.
(E) Injuries that occurred on the slopes of ski resorts made up a smaller percentage of ski-related injuries in 1980 than in 1950.

答案是E，E可以从文中推出。但B为什么不行？文中最后一句话说了: ... increases with the amount of alcohol consumed per skier.由此推出B行不行？

braveMBA

我试试：

The incidence of these injuries, including accidents such as falling down steps, increases with the amount of alcohol consumed per skier. 中的these injuries指的是the remainder of ski-related injuries，并不是全集，因为没有包括injuries that occur on the slopes ，所以不能推出B一定成立。

tocean0222

As the argument states, we can only know that the incidence of injuries other than injuries occuring on the slope increases with the amount of alcohol consumed per skier,  it does not mean that the amount of alcohol consumed per skier increased.Thus, B cannot be induced by the evidence provided in the argument.


enjoy!

dl7801

这道题有点数学题的意味。
为了方便
把 injuries that occur on the slopes of ski resorts 设为 X
其他的 injuries 类型设为 Y
文章告诉我们，Y类型的增长与酒的消费增长正相关（酒消费增长，Y增长），所以如果选项 B（酒的消费增长了）成立的话，我们必须确定： Y类型伤害的 incidence（即个案）一定增长了。
可是，由题目我们知道 X 的 incidence 确实下降了，而 Y 在伤害类型中所占的比例的上升可能是由于 X 的下降造成的， Y 本身可能上升， 也可能没变， 如果Y没变的话， 酒的消费量当然也就没变，所以 选项 B 不一定正确。
（列个式子会很清晰： Y%=Y/(X+Y) ..... Y%从10% 上升到25%,  ）

fwjy

其实这道题的Key是：比例，或者说绝对值对应相对值。

题干：根本没说过各种类型的injuries的绝对数量的变化，每次给的都是个相对值。

“from 9 injuries per 1,000 skiers in 1950 to 3 in 1980”，讲的是相对值的变化。

迷惑点是“has brought a dramatic drop in the incidence of injuries”这里的迷惑之处在于表达的含糊，到底是整体绝对下降还是相对值下降，没讲清楚。

“rose from 10 percent of all ski-related injuries in 1950 to 25 percent in 1980.”又是一个相对值的变化。

再看迷惑点：“The incidence of these injuries, including accidents such as falling down steps, increases with the amount of alcohol consumed per skier.”这里提绝对值变化，事故数与酒的消费量成正比。

整个题干里提到的事故数值的变化都是相对值的变化，或者说是比例值的变化。

看选项：

(A)得出绝对值比较的结论。排除。

(B)针对第二个迷惑点，得出绝对值比较的结论。但是不能得出“the remainder of ski-related injuries”的绝对数目增加而推出酒的消费量的增加的结论。排除。

(C)从题干上看，只影响了第一种类型的事故。排除。

(D)针对第一个迷惑点，得出一个绝对值比较的结论。排除。

(E)唯一进行相对值比较的结论，而且合理。所以是正确答案。