GWD里面的，我实在不会，请大家帮帮我

The higher the level of certain vitamins and minerals in the bloodstream, the better a person's lung function, as measured by the amount of air the person can expel in one second.  The lung function of smokers is significantly worse, on average, than that of nonsmokers.  Clearly, therefore, one way for smokers to improve their lung function is for them to increase their intake of foods that are rich in these helpful vitamins and minerals.

Which of the following is an assumption on which this argument depends?

(A) Smokers are less likely than nonsmokers to have diets that are rich in vitamins and minerals.

(B) The lung function of smokers whose diets are rich in those vitamins and minerals is generally better than that of nonsmokers with comparable diets.

(C) People whose diets are deficient in those vitamins and minerals do not typically have other health problems in addition to diminished lung function.

(D) Stopping smoking will not typically improve lung function more than any diet changes can.

(E) Smoking does not introduce into the body chemicals that prevent the helpful vitamins and minerals from entering the bloodstream.

答案选E，我觉得可以理解，但是我不明白为什么A不对。请各位高人帮我讲解一下！

多谢！

21. Historian: We can learn about the medical history of individuals through chemical analysis of their hair. It is likely, for example, that Isaac Newton’s psychological problems were due to mercury poisoning; traces of mercury were found in his hair. Analysis is now being done on a lock of Beethoven’s hair. Although no convincing argument has shown that Beethoven ever had a venereal disease, some people hypothesize that venereal disease caused his deafness. Since mercury was commonly ingested in Beethoven’s time to treat venereal disease, if researchers find a trace of mercury in his hair, we can conclude that this hypothesis is correct.

Which one of the following is an assumption on which the historian’s argument depends?

(A) None of the mercury introduced into the body can be eliminated.

(B) Some people in Beethoven’s time did not ingest mercury.

(C) Mercury is an effective treatment for venereal disease.

(D) Mercury poisoning can cause deafness in people with venereal disease.

(E) Beethoven suffered from psychological problems of the same severity as Newton’s

答案选B，我怎么也不明白到底是为什么？也不知道到底是怎么推出来的？

commonly ingested和no convincing argument，所以认为有一些人没有感染。

28. Ordinary mountain sickness, a common condition among mountain climbers, and one from which most people can recover, is caused by the characteristic shortage of oxygen in the atmosphere at high altitudes. Cerebral edema, a rarer disruption of blood circulation in the brain that quickly becomes life-threatening if not correctly treated from its onset, can also be caused by a shortage of oxygen. Since the symptoms of cerebral edema resemble those of ordinary mountain sickness, cerebral edema is especially dangerous at high altitudes.

Which one of the following is an assumption on which the argument depends?

(A) The treatment for ordinary mountain sickness differs from the treatment for cerebral edema.

(B) Cerebral edema can cause those who suffer from it to slip into a coma within a few hours.

(C) Unlike cerebral edema, ordinary mountain sickness involves no disruption of blood circulation in the brain.

(D) Shortage of oxygen at extremely high altitude is likely to affect thinking processes and cause errors of judgment.

(E) Most people who suffer from ordinary mountain sickness recover without any special treatment.

convicted of a serious driving-relative offense should either be sentenced to jail or be forced to receive driver reeducation, since to do otherwise would be to allow a crime to go unpunished. Only if such drivers are likely to be made more responsible drivers should driver re-education be recommended for them. Unfortunately, it is always almost impossible to make drivers with a large number of demerit points more responsible drivers.

If the editorialist’s statements are true, they provide the most support for which one of the following?

(A) Drivers with a large number of demerit points who have been convicted of a serious driving-related offense should be sent to jail.

(B) Driver re-education offers the best chance of making drivers with a large number of demerit points responsible drivers.

(C) Driver re-education is not a harsh enough punishment for anyone convicted of a serious driving-related offense who has also

(D) Driver re-education should not be recommended for those who have committed no serious

(E) Drivers with a larger number of demerit points but no conviction for a serious driving-related offense should receive driver re-education rather than jail

38. Amphibian populations are declining in numbers worldwide. Not coincidentally, the earth’s ozone layer has been continuously depleted throughout the last 50 years. Atmospheric ozone blocks UV-B, a type of ultraviolet radiation that is continuously produced by the sun, and which can damage genes. Because amphibians lack hair, hide, or feathers to shield them, they are particularly vulnerable to UV-B radiation. In addition, their gelatinous eggs lack the protection of leathery or hard shells. Thus, the primary cause of the declining amphibian population is the depletion of the ozone layer.

Each of the following, if true, would strengthen the argument EXCEPT:

(A) Of the various types of radiation blocked by atmospheric ozone, UV-B is the only type that can damage genes.

(B) Amphibian populations are declining far more rapidly than are the populations of nonamphibian species whose tissues and eggs have more natural protection from UV-B.

(C) Atmospheric ozone has been significantly depleted above all the areas of the world in which amphibian populations are declining.

(D) The natural habitat of amphibians has not become smaller over the past century.

(E) Amphibian populations have declined continuously for the last 50 years.