Question

   A Canadian study suggests that current sodium (钠) intake levels are relatively safe for most Americans and that reducing them to the very low levels recommended by federal health officials and leading medical groups may harm a significant number.

   The current average sodium consumption in the United States is about 3,400 milligrams (there are 1,000 milligrams in one gram) per day. This is about the amount of sodium in about 1. 5 teaspoons of salt. Dietary guidelines offered by the federal government and leading medical groups recommend reducing the average to 2,300 milligrams for the general population and 1,500 for groups considered at greater risk,like adults older than 50,African-Americans,and people with high blood pressure,among others.

   However,previous studies have found little evidence to support those low recommended sodium targets. There is considerable evidence that lowering sodium can reduce blood pressure,but there is scant evidence that reducing sodium consumption will necessarily reduce the risk of heart attacks, strokes(中 风) and death.

   Now a large study by researchers at McMaster University in Ontario,Canada,which tracked more than 100,000 people from 17 countries on five continents,has found that the safest levels of sodium intake are between 3 ,000 and 6,000 milligrams. Consumption below that level showed increased risk of death and cardiovascular(心血管的) events.

Roughly 10 percent of the patients followed in the study fell below 3,000 milligrams,a sizable number to put at risk.

   Brian Strom,honorary head of biomedical and health sciences at Rutgers University,who led a group of experts who reviewed the data on sodium for the Institute of Medicine last year,said that the new McMaster data are among the best available and that no study has shown a benefit from reducing sodium consumption to below 2,300 milligrams a day.

   That does not mean individuals wiiose sodium intake is high should not take steps to bring it down. The McMaster researchers say that if your blood pressure rises beyond the normal level (140/90 or higher) or your sodium intake is high,you should reduce sodium consumption,perhaps even to below 5 ,000 milligrams.

6. For healthy elderly people,the US government recommends sodium intake .

   A. 1,500 milligrams daily

   B. 2,300 milligrams daily

   C. 3,000 milligrams daily

   D. 3,400 milligrams daily

7. The underlined word “scant” in Paragraph 3 is closest in meaning to “”.

   A. direct   B. important

   C. limited   D. conflicting

8. According to the study,consuming less than 3,000 milligrams of sodium a day.

   A. is beneficial for most patients

   B. may help prevent heart disease

   C. may be harmful to your health

   D. is especially helpful for Americans

9. What is Strom's attitude towards the research findings?

   A. He is doubtful about them.

   B. He is uncertain of them.

   C. He tolerates them.

   D. He supports them.

10. What is the Canadian scientists’ advice for high blood pressure patients?

   A. Follow the government's dietary guidelines.

   B. Lower sodium intake to a reasonable level.

   C. Join one of the leading medical groups.

   D. Have physical examinations regularly.

Answer 1

6. A 7. C 8. C 9. D 10. B

(健康)

本文是说明文。研究表明过度降低食物盐分对身体有害。

6. A.推理判断题。由第二段中的 1.500 for groups considered at greater risk,like adults older than 50 可知，美ft政府建议健康的老人每一天食用1500毫克钠。

7. C.词义猜测题。由第三段该词所 在句中的but可知，scant与con-siderable (相当多的) 意思相反，故 选C项。

8. C.细节理解题。由第四段中的 Consumption below that level showed increased risk of death and cardiovascular events可知，该研究认为,每天食用少于3000毫克的钠 对健康不利。

9. D.推理判断题。由倒数第二段中 的 the new McMaster data are among the best available and that no study has shown a benefit from reducing spdium consumption to below   2.300 milligrams a day.可知， Strom支诗该研究结果。

10. B.细节理解题。由最后一段可知，这些加拿大科学家建议高血 .压患者适当降低钠的摄入量。