请教LSAT-13-I-12,16

joywzy

12. In 1980 health officials began to publicize the adverse effects of prolonged exposure to the sun, and since then the number of people who subathe for extended periods of time has decreased considerably each year. Nevertheless, in 1982 there was a dramatic rise in newly reported cases of melanoma, a form of skin cancer found mostly in people who have had prolonged exposure to the sun.

Which one of the following, if true, helps to resolve the apparent discrepancy in the information above?

(A) Before 1980 a considerable number of the people who developed melanoma as a result of prolonged exposure to the sun were over forty years of age.

(B) Before1980, when most people had not yet begun to avoid prolonged exposure to the sun, sunbathing was widely thought to be healthful.

(C) In 1982 scientists reported that the body’s need for exposure to sunlight in order to produce vitamin D, which helps prevent the growth of skin cancers, is less than was previously though.

(D) In 1982 medical researchers perfected a diagnostic technique that allowed them to detect the presence of melanoma much earlier than had previously been possible.

(E) Since 1980, those people who have continued to sunbathe for extended periods of time have used sunblocks that effectively screen out the ultraviolet rays that help cause melanoma.

答案：D，解释矛盾点：日光浴的少了，得皮肤病的多了 。D是可以解释的。
但是C呢？从1982年后，又宣传日光浴，所以晒日光浴的多了，得皮肤病的人多了。
哪里不对呢？


Salmonella is a food-borne microorganism that can cause intestinal illness. The illness is sometimes fatal, especially if not identified quickly and treated. Conventional Salmonella tests on food samples are slow and can miss unusual strains of the microorganism. A new test identifies the presence or absence of Salmonella by the one piece of genetic material common to all strains. Clearly, public health officials would be well advised to replace the previous Salmonella tests with the new test.

16. Which one of the following, if true, most substantially weakens the argument?

(A) The new test identifies genetic material from Salmonella organisms only and not from similar bacteria.

(B) The new test detects the presence of Salmonella at levels that are too low to pose a health to people.

(C) Salmonella is only one of a variety of food-borne microorganism that can cause intestinal illness.

(D) The new test has been made possible only recently by dramatic advances in biological science.

(E) Symptoms of Salmonella poisoning are often mistaken for those of other common intestinal illness.

答案：B

原文：new test: quick + test all  strains , so new test is better than old one.

B是说明了新的测试不足,但与原文的LINK无关啊？

我选了A：A说明新的测试只能试部分的strain，不是削弱了吗？

谢谢

wdzc

12.我对C选项的理解是:为了获得Vitamin D,需要晒太阳的时间比以前认为的少.那也应该是晒太阳时间少,得皮肤病的人少了.

wdzc

第二道:排除法,我觉得A.C,D,E都是无关选项.
A中提到别的similar bacteria,而原文中提到的全是Salmonella.

mike1999

第一题，你对C的理解有误。
(C) In 1982 scientists reported that the body’s need for exposure to sunlight in order to produce vitamin D, which helps prevent the growth of skin cancers, is less than was previously though.意思是说1982年科学家们发现人们可以不要晒太久的太阳已获得v d.
所以它最多能的得出这样一个结论：人们会晒更少的太阳。
这并不能解释提干中的皮肤癌的病患增加。
第二题：一样还是理解上的问题
(B) The new test detects the presence of Salmonella at levels that are too low to pose a health to people. 的意思是新测试方法能测试到的对人类无害的的S.既然无害当然就没有必要测试了。
A) The new test identifies genetic material from Salmonella organisms only and not from similar bacteria.说新方法只能测出S的基因物质而不能测试其他类似细菌的存在，提干中并没有说测不出类似病菌就会带来什么后果阿，千万不要自己推理。既然可以测出S，那就足够了。

joywzy

看来，是我对句子的理解上有问题。

谢谢wdz，mike1999。