A、Couples living together. B、Gay couples. C、The divorced. D、The widowed. D细节辨认题。本题可采用排除法。文中提到他的研究与现实已经不相符合，因为他的三种分类不包括同居者、同性恋伴侣、

In 1858, a British scientist named William Farr set out to study the "marital condition" of the people of France. He divided the adults into three categories: the "married", consisting of husbands and wives; the "unmarried", defined as the bachelors and spinsters who had never married; and finally the "widowed", those who had experienced the death of a spouse. (29)Using birth, death and marriage records, Farr analyzed the death rates of the three groups at various ages. The work, a groundbreaking study that helped establish the field of medical statistics, showed that much more unmarried people died from disease than the married. And the widowed, Farr found, lived worst of all.
      Farr was among the first scholars suggesting that there is a health advantage to marriage. Married people, the data seemed to show, lived longer, healthier lives. "Marriage is a healthy estate," Farr concluded. "The single individual is more likely to be wrecked on his voyage than the lives joined together in marriage."
      (30) While Farr’s own study is no longer relevant to the social realities of today’s world because his three categories don’t include couples living together, gay couples and the divorced, for instance, his finding about the health benefits of marriage seems to have stood the test of time. (31)Although better health among the married some times simply reflects the fact that healthy people are more likely to get married in the first place, scientists have continued to prove the "marriage advantage": the fact that married people, on average, appear to be healthier and live longer than unmarried people.