时间:2012-10-29 21:07:44
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.
参考答案：B
37. Caffeine is used to
A. reduce high blood pressure.
B. relieve headaches.
C. cure liver cancer.
D. treat skin cancer.
参考答案：B
38. Some athletes use caffeine to
A. improve their speed.
B. increase their endurance.
C. maintain their alertness.
D. relax their muscles.
参考答案：B
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.
参考答案：D
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.
参考答案：C
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 more, and also because it is needed to block other unpleasant tastes in food.” said Hayes. "Supertasters, people who experience tastes more intensely, consume more salt than do nontasters. Snack foods have saltiness as their primary flavor, and at least for these foods, more is better, so the supertasters seem to like them more.”
However, supertasters also need higher levels of salt to block unpleasant bitter tastes in foods such as cheese, Hayes noted. "For example, cheese is a wonderful blend of dairy flavors from fermented milk, but also bitter tastes from ripening that are blocked by salt," he said. "A supertaster finds low-salt cheese unpleasant because the bitterness is too pronounced."
Hayes cited research done more than 75 years ago by a chemist named Fox and a geneticist named Blakeslee, showing that individuals differ in their ability to taste certain chemicals. As a result, Hayes explained, we know that a wide range in taste acuity exists, and this variation is as normal as variations in eye and hair color.
"Some people, called supertasters, describe bitter compounds as being extremely bitter, while others, called nontasters, find these same bitter compounds to be tasteless or only weakly bitter." he said. "Response to bitter compounds is one of many ways to identify biological differences in food preference because supertasting is not limited to bitterness.”
41. John Hayes points out in a recent study that
A. it is healthy to eat food without salt.
B. many people reject low-salt food completely.
C. food with less salt tastes better.
D. many people accept low-salt tasteless food reluctantly.
参考答案：D
42. The fourth paragraph describes briefly
A. the purpose of the study.
B. the analysis of the research results.
C. the research methodology.
D. the conclusion of the study.
参考答案：C
43. The article argues that supertasters
A. like snack foods as saltiness is their primary flavor.
B. like the taste of saltiness to block sweet tastes in food.
C. consume less salt because they don't like intensive tastes.
D. like to share salty cheese with nontasters.
参考答案：A
44. In paragraph 6, the word "pronounced" is closest in meaning to
A. weary.
B. strong.
C. weak.
D. strange.
参考答案：B
45. The last two paragraphs illustrate that taste acuity is
A. developed over time after birth.
B. related to one's eye and hair color.
C. still unknown to scientists.
D. genetically determined.
参考答案：D