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阅读理解题在考研中比重很大,考生在复习的时候要多做阅读理解多做练习,下面太奇考研通过具体的实例,分享一下考研英语阅读理解的剖析方法以及答题技巧。
A boy or a girl? That is usually the first question asked when awoman gives birth. Remarkably, the answer varies with where the mother lives.In rich countries the chances of its being a boy are about 5% higher than inpoor ones. Equally remarkably, that figure has been falling recently. Severaltheories have been put forward to explain these observations. Some argue thatsmoking plays a role, others that diet may be important. Neither of these ideashas been supported by evidence from large studies. But new research points to adifferent factor: stress.
Strange as it might seem, the terrorist attacks of September 11th2001 shed light on the enigma. Studies noting the sex of babies conceived inNew York during the week of the attacks found a drop in the ratio of males tofemales. That is consistent with earlier studies, which revealed a similarshift in women who became pregnant during floods and earthquakes and in time ofwar. Moreover, a study carried out eight years ago by researchers at theUniversity of Aarhus, in Denmark, revealed that women who suffered the death ofa child or spouse from some catastrophic illness around the time they conceivedwere much more likely to give birth to girls than to boys.
Taken together, these results suggest that acute stress to a womanat the time of conception shifts the sex ratio towards girls. However, CarstenObel, a researcher at Aarhus who was not involved in the earlier study,wondered if the same might be true of chronic stress too. In a paper justpublished in Human Development, he shows that it is.
Dr Obel used a set of data collected between 1989 and 1992. Duringthat period 8,719 expectant mothers were asked to fill in questionnaires thatinquired, among other things, about their level of stress. Dr Obel found thatthe more stressed a mother had been, the less chance she had of having givenbirth to a boy. Only 47% of children born to women in the top quartile ofstress were males. That compared with 52% for women in the bottom quartile. DrObel suspects the immediate cause is that male pregnancies are more likely tomiscarry in response to stress than female pregnancies are, especially duringthe first three months. However, that is difficult to prove. More intriguing,though, is the ultimate cause, for he thinks it might be adaptive, rather thanpathological.
That is because the chances are that a daughter who reachesadulthood will find a mate and thus produce grandchildren. A son is a differentmatter. Healthy, strapping sons are likely to produce lots of grandchildren, byseveral women-or would have done in the hunter-gatherer societies in which mosthuman evolution took place. Weak ones would be marginalised and maybe evenkilled in the cut and thrust of male competition. If a mother’s stressadversely affects the development of her fetus then selectively aborting boys,rather than wasting time and resources on bringing them to term, would makeevolutionary sense.
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