[求助]两道逻辑题，帮忙看看为什么选择哪个答案。谢谢

yiyuandong

[em26]After the national speed limit of 55 miles per hour was imposed in 1974, the number of deaths per mile driven on a highway fell abruptly as a result. Since then, however, the average speed of vehicles on highways has risen, but the number of deaths per mile driven on a highway has continued to fall.
Which of the following conclusions can be properly drawn from the statements above?
(A) The speed limit alone is probably not responsible for the continued reduction in highway deaths in the years after 1974.
(B) People have been driving less since 1974.
(C) Driver-education courses have been more effective since 1974 in teaching drivers to drive safely.
(D) In recent years highway patrols have been less effective in catching drivers who speed.
(E) The change in the speed limit cannot be responsible for the abrupt decline in highway deaths in 1974.


[em26]Reviewing historical data, medical researchers in California found that counties with the largest number of television sets per capita have had the lowest incidence of a serious brain disease, mosquito-borne encephalitis. The researchers have concluded that people in these counties stay indoors more and thus avoid exposure to the disease.
The researchers’ conclusion would be most strengthened if which of the following were true?
(A) Programs designed to control the size of disease-bearing mosquito populations have not affected the incidence of mosquito- borne encephalitis.
(B) The occupations of county residents affect their risk of exposure to mosquito-borne encephalitis more than does television-watching.
(C) The incidence of mosquito-borne encephalitis in counties with the largest number of television sets per capita is likely to decrease even further.
(D) The more time people in a county spend outdoors, the greater their awareness of the dangers of mosquito-borne encephalitis.
(E) The more television sets there are per capita in a county, the more time the average county resident spends watching television.

primefang

1 A
2 A

marine91

2应该是E,,,,A是部分weaken。e是桥。

primefang

marine91, 我的理解是, 原文的结论是,the more indoors, the less deceases. A 说明了不是由于电视造成的,所以正确.

请指教

spry

For the second one, the question says nothing about the program mentioned in the answer A, therefore A is not correct. The logic of the researchers is that more TV per capita==>stay indoor==>avoid exposure to the disease. But more TV per capita cannot guarantee that people spend more time watching TV indoor and Answer E meets the gap. Hence E is correct answer.

primefang

Thanks all above's contribution