Being a man has always been dangerous. There are about 105 males born for every 100 females , but this ratio drops to near balan

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问题     Being a man has always been dangerous. There are about 105 males born for every 100 females , but this ratio drops to near balance at the age of maturity, and among 70-year-olds there are twice as many women as men. But the great universal of male mortality is being changed. Now, boy babies survive almost as well as girls do. This means that, for the first time, there will be an excess of boys in those crucial years when they are searching for a mate. More important, another chance for natural selection has been removed. Fifty years ago, the chance of a baby (particularly a boy baby) surviving depended on its weight. A kilogram too light or too heavy meant almost certain death. Today it makes almost no difference. Since much of the variation is due to genes, one more agent of evolution has gone.
    There is another way to commit evolutionary suicide: stay alive, but have fewer children. Few people are as fertile as in the past. Except in some religious communities, very few women has 15 children. Nowadays the number of births, like the age of death, has become average. Most of us have roughly the same number of offspring. Again, differences between people and the opportunity for natural selection to take advantage of it have diminished. India shows what is happening. The country offers wealth for a few in the great cities and poverty for the remaining tribal peoples. The grand mediocrity of today—everyone being the same in survival and number of offspring—means that natural selection has lost 80% of its power in upper-middle-class India compared to the tribes.
    For us, this means that evolution is over; the biological Utopia has arrived. Strangely, it has involved little physical change. No other species fills so many places in nature. But in the past 100,000 years—even the past 100 years—our lives have been transformed but our bodies have not. We did not evolve, because machines and society did it for us. Darwin had a phrase to describe those ignorant of evolution; they "look at an organic being as a savage looks at a ship, as at something wholly beyond his comprehension." No doubt we will remember a 20th century way of life beyond comprehension for its ugliness. But however amazed our descendants may be at how far from Utopia we were, they will look just like us.
What can we learn from the second sentence in the first paragraph?

选项 A、Being a man has always been dangerous.
B、Men have a lower survival rate.
C、There are more women than men.
D、Men are more mature.

答案B

解析 第二句的意思是:在出生时,男女比例大约是105:100,但到了成熟期,这一比例下降到几乎持平,而在70岁的老人中,女性是男性的两倍。从这句话来看,男性从出生到70岁,人口比例是一直在下降,因此选项B是正确的。选项A对应的是文章第一句的内容,不是题目问的对象,属于所答非所问。选项C只是第二句中70岁男女比例的情况,不能代表整个第二句内容,属于断章取义。选项D是无中生有。
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