职称英语考试

试题来源：2012年职称英语等级考试真题（卫生类A级）
【单选题】

　　第三篇 Caffeine
　　Caffeine is probably the most widely used drug in the world. Humans have been consuming caffeine for hundreds of years, primarily in the form of coffee, tea, and cocoa. Habitual coffee and tea drinkers had long been observed to have a lower incidence of non-melanoma(黑色素瘤) skin cancers, although no one knew why. A recent study found that caffeine affects skin cells damaged by ultraviolet radiation, a main cause of skin cancer. Caffeine interferes with a protein that cancerous cells need to survive, leaving the damaged cells to die before they become cancerous. Drinking caffeinated coffee has also been associated with a decreased incidence of endometrial(予宫内膜的) cancer - that is, cancer of the cells lining the uterus - The strongest effect appears to be in overweight women, who are at greatest risk for the disease. Researchers believe blood sugar, fat cells, and estrogen(雌性激素) may play a role. Although the mechanism remains unknown, people who drink more than two cups of coffee or tea a day reportedly have about half the risk of developing chronic liver disease as those who drink less than one cup of coffee daily; caffeinated coffee has also been associated with lowered risk of cirrhosis(肝硬化) and liver cancer.
　　While many of caffeine's undesirable effects, such as elevated heart rate and blood pressure, are brief, some short-term benefits, including pain relief, increased alertness, and increased physical endurance, have also been attributed to caffeine. As a component of numerous over-the-counter diet pills and pain relievers, caffeine increases their effectiveness and helps the body absorb them more quickly. By constricting(收缩) blood vessels in the brain, it can alleviate headaches - even migraines(偏头痛) – and can help counter the drowsiness(眩晕)caused by antihistamines(抗组胺药).
　　Caffeine does not alter the need for sleep, but it does offer a temporary solution to fatigue for people who need to stay alert. Research has shown that sleep-deprived individuals who consumed caffeine had improved memory and reasoning abilities, at least in the short term. Studies of runners and cyclists have shown that caffeine can improve their stamina - hence its addition to energy-boosting sports drinks.
　　People who consume a lot of caffeine regularly may develop temporary withdrawal symptoms, headache being the most common, if they quit or cut back on it abruptly. Fortunately, these symptoms last only a day or two in most cases. Individuals who are more sensitive to the stimulatory side effects of caffeine may want to avoid it, but most doctors agree that the equivalent of three cups of coffee a day does not harm healthy people. There is no medical basis to give up daily caffeine and many reasons to include a moderate amount in one's diet.
　　41. Drinking coffee or tea may help
　　A. lower the incidence of non-melanoma skin cancer.
　　B. lower the incidence of being overweight .
　　C. increase the incidence of endometrial cancer.
　　D. increase the incidence of liver cancer.
　　42. Caffeine is used to
　　A. reduce high blood pressure.
　　B. cure liver cancer.
　　C. relieve headaches.
　　D. treat skin cancer.
　　43. Some athletes use caffeine to
　　A. increase their endurance
　　B. improve their speed.
　　C. maintain their alertness.
　　D. relax their muscles.
　　44. Caffeine withdrawal symptoms
　　A. can become an ongoing problem.
　　B. may last as long as a week.
　　C. are usually short-lived.
　　D. are weight loss and mental disorder.
　　45. Drinking three cups of coffee a day
　　A. may not be recommended by most doctors.
　　B. will probably not cause problems .
　　C. is harmful to healthy people.
　　D. may benefit sensitive people.

网考网参考答案：A、C、A、C、B
大数据分析：根据网考网与考试题库的统计分析，该试题：
28%的考友选择了A选项
48%的考友选择了B选项
13%的考友选择了C选项
11%的考友选择了D选项
考友解析与评论：
 · 没读清题就选了，多么简单的一题啊
 · 这题答案有争议，我认为选A、C、A、C、B
 · 我选了A、C、A、C、B，没有理由，就是A、C、A、C、B