单选题 We have heard a lot about the health benefits of tea, especially green tea. It is high in polyphenols, compounds with strong antioxidant activity that in test-tube and animal models show anticancer and heart-protective effects. Good clinical studies are few, however, and although physicians tell their patients to drink green tea, there hasn"t been any definite proof of the value of that advice.
A team of Japanese researchers was able to link green tea consumption with decreased mortality from many causes--including heart disease. The researchers tracked 40,530 healthy adults ages 40 to 79 in a region of northeastern Japan where most people drink green tea, following them for up to 11 years. Those who drank five or more cups of green tea a day had significantly lower mortality rates than those who drank less than one cup a day. There were also fewer deaths from cardiovascular disease.
But no such association was seen with deaths from cancer. Nor was consumption of oolong or black tea connected with any decrease in mortality. Those teas are easier to be combined with oxygen in processing, which not only darkens the color of the leaves and changes their flavor but also reduces their polyphenol content.
Coffee is more complicated. It has received both gold stars and black marks in medical literature. It, too, contains antioxidants, although they are less well studied than tea polyphenols. Evidence for the health benefits of coffee is growing, however. A group of investigators from Finland, Italy and the Netherlands reports that coffee seems to protect against age-related decline in mental capacity. The scientists studied 676 healthy men born from 1900 to 1920 and followed them for 10 years, using standardized measures of brain function. Their conclusion: the men who consumed coffee had significantly less decline in mental capacity than those who didn"t. Three cups a day seemed to provide the most protection.
Population studies like those help us form assumptions about relationships between dietary habits and long-term health. We still have to test our suppositions in controlled conditions, and measure the effects of coffee and tea on various systems of the body.

单选题 Physicians often tell their patients to drink green tea because ______.

【正确答案】 B

【答案解析】[解析] 推断题。从文章第一段第一句“We have heard a lot about the health benefits of tea, especially green tea.”及第三句“Good clinical studies are few, however, and although physicians tell their patients to drink green tea, there hasn"t been any definite proof of the value of that advice．”可知，医生建议病人多喝绿茶并没有确切的数据证明这个建议的有效性，只是据说绿茶对人体健康有好处，故选B。

单选题 The Japanese study seems to have confirmed the positive effect of green tea on ______.

【正确答案】 D

【答案解析】[解析] 细节题。从文章第二段第一句“A team of Japanese researchers was able to link green tea consumption with decreased mortality from many causes--including heart disease．”及第三句 “Those who drank five or more cups of green tea a day had significantly lower mortality rates than those who drank less than one cup a day．”可知，日本研究者将饮用绿茶与诸如心脏病等因素导致的死亡率下降相联系，与每天饮用不到一杯绿茶的人相比，每天饮用五杯以上绿茶的人的死亡率要低得多，故选D。

单选题 The text indicates that black tea differs from green tea in that ______.

单选题 Coffee is beneficial to one"s health because ______.

【正确答案】 B

【答案解析】[解析] 细节题。从文章第四段第五句“A group of investigators from Finland, Italy and the Netherlands reports that coffee seems to protect against age-related decline in mental capacity.”及第七句“Their conclusion: the men who consumed coffee had significantly less decline in mental capacity than those who didn"t．”可知，咖啡可以降低老化引起的智力衰退的速度，故选B。

单选题 The text indicates that the relationships between dietary habits and long-term health ______.

【正确答案】 C

【答案解析】[解析] 推断题。从文章最后一句话“We still have to test Our suppositions in controlled conditions，and measure the effects of coffee and tea on various systems of the body．”可知，我们要对这些假设在可控环境下进行测试，并测量咖啡和茶对人体各系统的影响，由此可推断出饮食习惯与长期健康的关系还是要进一步进行试验，故选C。