The best evidence to date concerns folate, one of the B vitamins. It's been proved to limit the number of defects in embryos (胚胎), and a recent trial found that folate in combination with vitamin B 12 and a form of B6 also decreases the re-blockage of arteries after surgical repair.
The news on vitamin E has been more mixed. Healthy folks who take 400 international units daily for at least two years appear somewhat less likely to develop heart disease. But when doctors give vitamin E to patients who already have heart disease, the vitamin doesn't seem to help. It may turn out that vitamin E plays a role in prevention but cannot undo serious damage.
编辑推荐：
2011年6月大学英语六级网上报名入口
2011年大学英语六级考试阅读理解专项训练35篇汇总
英语六级考试考前备考时间分配原则介绍
www.dxs89.com
Despite vitamin C's great popularity, consuming large amounts of it still has not been positively linked to any great benefit. The body quickly becomes saturated with C and simply excretes (排泄) any excess.
The multivitamins question boils down to this: Do you need to wait until all the evidence is in before you take them, or are you willing to accept that there's enough evidence that they don't hurt and could help?
If the latter, there's no need to go to extremes and buy the biggest horse pills or the most expensive bottles. Large doses can cause trouble, including excessive bleeding and nervous system problems.
Multivitamins are no substitute for exercise and a balanced diet, of course. As long as you understand that any potential benefit is modest and subject to further refinement, taking a daily multivitamin makes a lot of sense.
21. At one time doctors discouraged taking multivitamins because they believed that multivitamins ____.
A) could not easily be absorbed by the human body
B) were potentially harmful to people's health
C) were too expensive for daily consumption
D) could not provide any cure for vitamin deficiencies
22. According to the author, clinical trials of vitamin supplements ____.
A) often result in misleading conclusions
B) take time and will not produce conclusive results
C) should be conducted by scientists on a larger scale
D) appear to be a sheer waste of time and resources
23. It has been found that vitamin E _____.
A) should be taken by patients regularly and persistently
B) can effectively reduce the recurrence of heart disease
C) has a preventive but not curative effect on heart disease
D) should be given to patients with heart disease as early as possible
24. It can be seen that large doses of multivitamins _____.
A) may bring about serious side effects
B) may help prevent excessive bleeding
C) are likely to induce the blockage of arteries
D) are advisable for those with vitamin deficiencies
25. The author concludes the passage with the advice that _____.
A) the benefit of daily multivitamin intake outweighs that of exercise and a balanced diet
B) it's risky to take multivitamins without knowing their specific function
C) the potential benefit of multivitamins can never be overestimated
D) it's reasonable to take a rational dose of multivitamins daily
Passage Two
Questions 26 to 30 are based on the following passage.
Some futurologists have assumed that the vast upsurge (剧增) of women in the workforce may portend a rejection of marriage. Many women, according to this hypothesis, would rather work than marry. The converse (反面) of this concern is that the prospects of becoming a multi-paycheck household could encourage marriages. In the past, only the earnings and financial prospects of the man counted in the marriage decision. Now, however, the earning ability of a woman can make her more attractive as a marriage partner. Data show that economic downturns tend to postpone marriage because the parties cannot afford to establish a family or are concerned about rainy days ahead. As the economy rebounds, the number of marriages also rises.
Coincident with the increase in women working outside the home is the increase in divorce rates. Yet, it may be wrong to jump to any simple cause-and-effect conclusions. The impact of a wife's work on divorce is no less cloudy than its impact on marriage decisions. The realization that she can be a good provider may increase the chances that a working wife will choose divorce over an unsatisfactory marriage. But the reverse is equally plausible. Tensions grounded in financial problems often play a key role in ending a marriage. Given high unemployment, inflationary problems, and slow growth in real earnings, a working wife can increase household income and relieve some of these pressing financial burdens. By raising a family's standard of living, a working wife may strengthen her family's financial and emotional stability.
Psychological factors also should be considered. For example, a wife blocked from a career outside the home may feel caged in the house. She may view her only choice as seeking a divorce. On the other hand, if she can find fulfillment through work outside the home, work and marriage can go together to create a stronger and more stable union.
Also, a major part of women's inequality in marriage has been due to the fact that, in most cases, men have remained the main breadwinners. With higher earning capacity and status occupations outside of the home comes the capacity to exercise power within file family. A working wife may rob a husband of being the master of the house. Depending upon how the couple reacts to these new conditions, it could create a stronger equal partnership or it could create new insecurities.
26. The word "portend" (Line 2, Para. 1) is closest in meaning to “_____”.
A) defy C) suffer from
B) signal D) result from
27. It is said in the passage that when the economy slides, _____.
A) men would choose working women as their marriage partners
B) more women would get married to seek financial security
C) even working women would worry about their marriages
D) more people would prefer to remain single for the time being
28. If women find fulfillment through work outside the home, _____.
A) they are more likely to dominate their marriage partners
B) their husbands are expected to do more housework
C) their marriage ties can be strengthened
D)they tend to put their career before marriage
29. One reason why women with no career may seek a divorce is that _____.
A) they feel that they have been robbed of their freedom
B) they are afraid of being bossed around by their husbands
C) they feel that their partners fail to live up to their expectations
D) they tend to suspect their husbands' loyalty to their marriage
30. Which of the following statements can best summarize the author's view in the passage?
A) The stability of marriage and the divorce rate may reflect the economic situation of the country.