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问题 单项选择题 A1型题

在下列哪期缺乏碘可引起地方性克汀病（）

A.胎儿期

B.幼儿期

C.儿童青少年期

D.青春发育期

E.青年期

答案

参考答案：A

解析：地方性克汀病endemiccretinism生长发育迟缓；表情呆滞；智力低下；甲状腺肿；便秘。粘液性水肿地方性克汀病（endemiccretinism）多出现在严重的地方性甲状腺肿流行区，该区至少有1／5人群患有甲状腺肿，一般患病率占甲状腺肿地区人口的1～5％，严重地区高达5～10％。本病是胚胎时期和出生后早期碘缺乏与甲状腺功能低下所造成的大脑与中枢神经系统发育分化障碍的结果。

选择题

向AgCl饱和溶液中加入NaI溶液出现的现象是（　　）

A．.白色沉淀转化为黑色

B．无明显变化

C．白色沉淀转化为黄色

D．不能发生沉淀转化
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单项选择题

At the beginning of the twentieth century, North American society held, as an ideal, the Nuclear Family. This presumably perfect residential, social, and economic unit consisted of an adult male, an adult female and their minor children. This structure was thought to be stable and long lasting.
However, a few decades later, the structure of that ideal family was being altered radically even while it was being touted as the structure to be aimed for. Popular magazines bemoaned the loss of the Nuclear Family and its replacement with inferior forms.
There are a number of factors that are acting in concert to apply pressure on the Nuclear Family and generate a variety of new structures. Some of these are:
The definition of marriage has changed somewhat in that few people now consider it to last "until death do us part". The concept of monogamy (the marriage of one man and one woman) has been modified to a form now referred to as serial monogamy (the marriage of one man and one woman at a time). This reflects the increasing equality of women and men in terms of economic advantage and the recognition that many women no longer depend on men for their survival. Women are acquiring independence and have become empowered to make their own choices. With this independence, the need to form a relationship with a man becomes less important. This change embodies the concept that the marriage is temporary and can be terminated by either partner at any time. Associated with this, of course, is the relaxation of the divorce laws and the significant reduction of the shame that had one time been attached to divorce
The economy of North America has resulted in a two-tier system of a few rich who control most of the resources and a large portion of the population who control almost none of the resources. Because of this, many couples are forced to have both partners with full-time jobs outside the home. There are unintended byproducts of the need for a double income. The most important of these is the replacement of a mother-oriented socialization of children to a "stranger-oriented" socialization system reflected in the growth of the childcare industry. Also, either partner is financially able to end the marriage without significant hardship.
The combination of these changes will in the coming decades have a profound effect on the structure of the family of North America. As a result, the family will be a fluid, constantly changing structure with variable household arrangements as the norm.

In the 1910s most North Americans believed that the Nuclear Family ______.

A．wouldn’t last long

B．was the normal family structure

C．had no social and economic basis

D．was unworthy
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