单选题
More about Alzheimer"s Disease

Scientists have developed skin tests that may be used in the future to identity people with Alzheimer"s disease and may ultimately allow physicians to predict who is at risk of getting this neurological (神经病学的) disorder.
The only current means of diagnosing the disease in a living patient is a long and expensive series of tests that eliminate every other cause of dementia.
"Since Alois Alzheimer described the disease nearly a century ago, people have been trying to find a way to accurately diagnose it in its early stages," said Patricia Grady, acting director of the National Institute of Neurological Disorders and Stroke in Bethesda, Maryland. "This discovery, if confirmed, could prove a big step forward in our efforts to deal with and understand the disease."
Alzheimer"s is the single greatest cause of mental deterioration in older people, affecting between 2.5 million and 4 million people in the United States alone. The devastating disorder gradually destroys memory and the ability to function, and eventually causes death. There is currently no known treatment for the disease.
Researchers discovered that the skin cells of Alzheimer"s patients have defects that interfere with their ability to regulate the flow of potassium in and out of the cells. The fact that the cell defects are present in the skin suggests that Alzheimer"s results from physiological changes throughout the body, and that dementia may be the first noticeable effect of these changes as the defects affect the cells in the brain, scientists said.
The flow of potassium is especially critical in cells responsible for memory formation. The scientists also found two other defects that affect the cells" supply of calcium, another critical element.
One test developed by researches calls for growing skin cells in a laboratory culture and then testing them with an electrical detector to determine if the microscopic tunnels that govern the flow of potassium are open. Open potassium channels create a unique electrical signature.
A spokesman for the Alzheimer"s Association said that if the validity of the diagnostic test can be proven it would be an important development, but he cautioned that other promising tests for Alzheimer"s have been disappointing.
单选题 The newly developed skin tests may be used in the future to allow doctors to ______.
【正确答案】 C
【答案解析】[解析] 由文章第一段的内容可知,皮肤试验的最终目的在于“ultimately allow physicians to predict who is at risk of getting this neurological disorder”,所以只有C项符合题意。
单选题 The passage indicates that Alzheimer"s is a disease ______.
【正确答案】 D
【答案解析】[解析] 根据文章第二段的内容可知,老年痴呆症很难确诊,它的诊断是一个漫长且代价昂贵的过程。故D项正确。
单选题 Which of the following statements about the Alzheimer"s disease is NOT true?
【正确答案】 D
【答案解析】[解析] 由文章第四段最后一句“There is currently no known treatment for the disease. ”可知,目前还没有针对该病的确切疗法。D项的内容与此不符,故选D。
单选题 What is the relationship between Alzheimer"s and dementia?
【正确答案】 A
【答案解析】[解析] 第五段中谈到了两者的关系:“Alzheimer"s results from physiological changes...and that dementia may be the first noticeable effect of these changes...”,也就是说痴呆病是老年痴呆症的表现之一。
单选题 The last paragraph implies that the diagnostic test ______.
【正确答案】 C
【答案解析】[解析] 最后一段发言人谈到这一试验的前途时较为含蓄,只说试验如能证明有效自然是一大发展,但他同时提醒人们以前的试验看上去也很有前途,结果却令人失望。因此,只有C项符合题意。