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考试吧整理“GRE阅读理解模拟试题练习”更多GRE阅读考试复习指导等，请访问考试吧GRE考试网！ 8.People whose bodies cannot produce the substance cytochrome P450 are three times as likely to develop Parkinson\'s disease, a disease that affects the brain,as are people whose bodies do produce this substance.Since cytochrome P450 protects the brain from toxic chemicals, toxic chemicals probably play a role in the development of Parkinson\'s disease. Which of the following, if true, most strongly supports the argument? (A)It will soon be possible for cytochrome P450 to be synthesized for the treatment of people whose bodies cannot produce this substance. (B)Many people whose bodies are unable to produce cytochrome P450 lack the ability to produce certain other substances as well. (C)Cytochrome P450 has no effect on the brain other than to protect it from toxic chemicals. (D)People with Parkinson\'s disease often exhibit a marked lessening in the severity of their symp-toms when they are treated with dopamine, a chemical produced naturally in the brain. (E)Many people with Parkinson\'s disease have the ability to produce cytochrome P450 naturally. 9.The early universe contained only the lightest elements, hydrogen and helium. Heavier elements,such as carbon, form only in nuclear reactions in stars and are dispersed when the stars explode. A recently discovered gas cloud contained carbon several billion years ago, when the universe was no more than two billion years old. | 
