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.

36. Drinking coffee or tea may help

A. lower the incidence of being overweight.

B. lower the incidence of non-melanoma skin cancer.

C. increase the incidence of endometrial cancer.

D. increase the incidence of liver cancer.

37. Caffeine is used to

A. reduce high blood pressure.

B. relieve headaches.

C. cure liver cancer.

D. treat skin cancer.

38. Some athletes use caffeine to

A. improve their speed.

B. increase their endurance.

C. maintain their alertness.

D. relax their muscles.

39. Caffeine withdrawal symptoms

A. can become an ongoing problem.

B. may last as long as a week.

C. are weight loss and mental disorder.

D. are usually short-lived.

40. Drinking three cups of coffee a day

A. may not be recommended by most doctors.

B. is harmful to healthy people.

C. will probably not cause problems.

D. may benefit sensitive people.

【答案】：BBBDC

第三篇                 

Some People Do Not Taste Salt Like Others

    Low-salt foods may be harder for some people to like than others, according to a study by a Penn State College of Agricultural Sciences food scientist. The research indicates that genetic factors influence some of the difference in the levels of salt we like to eat.

    Those conclusions are important because recent, well-publicized efforts to reduce the salt content in food have left many people struggling to accept fare that simply does not taste as good to them as it does to others, pointed out John Hayes, assistant professor of food science, who was lead investigator on the study.

    Diets high in salt can increase the risk of high blood pressure and stroke. That is why public health experts and food companies are working together on ways to help consumers lower salt intake through foods that are enjoyable to eat. This study increases understanding of salt preference and consumption.

    The research involved 87 carefully screened participants who sampled salty foods such as soup and chips, on multiple occasions, spread out over weeks. Test subjects were 45 men and 42 women, reportedly healthy, ranging in age from 20 to 40 years. The sample was composed of individuals who were not actively modifying their dietary intake and did not smoke cigarettes. They rated the intensity of taste on a commonly used scientific scale, ranging from barely detectable to strongest sensation of any kind.

    "Most of us like the taste of salt. However, some individuals eat more salt, both because they like the taste of saltiness mo