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问题 应用设计题

按要求作图：如图所示杠杆OBA处于平衡状态，请分别画出F1的力臂l1和F2的力臂l2．

答案

如图所示

题目分析：从支点O分别向力F1和F2的作用线作垂线，支点O到垂足间的距离就是力臂，画法如图。

考点:力臂的画法

单项选择题

Anthropology is the study of human beings as creatures of society. It (1) its attention upon those. physical characteristics and industrial techniques, those conventions and values, which (2) one community from all others that belong to a different tradition.

The distinguishing mark of anthropology among the social sciences is that it includes for serious study other societies (3) our own. For its purposes any social (4) of mating and reproduction is as significant as our own. To the anthropologist our customs and those of a New Guinea tribe are two possible social schemes for (5) a common problem, and in so far as he remains an anthropologist he is (6) to avoid any weighting of one (7) the other. He is interested in human behavior, not as it is shaped by one tradition, our own, but as it has been shaped by any tradition (8) He is interested in a wide (9) of custom that is found in various cultures, and his object is to understand the way in which these cultures change and (10) , the different forms through which they express themselves and the (11) in which the customs of any peoples function in the lives of the (12) .

Now custom has not been commonly regarded as a (13) of any great moment. The inner workings of our own brains we feel to be uniquely (14) of investigation, but custom, we have a way of thinking, is behavior at its most commonplace. (15) , it is the other way round. Traditional custom is a mass of detailed behavior more astonishing than (16) any one person can ever evolve in individual actions. Yet that is a rather (17) aspect of the matter. The fact (18) first rate importance is the predominant role that custom (19) in experience and belief, and the very great varieties it may (20)

15（）

A. As a matter of fact

B. On the whole

C. In general

D. On the other hand
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选择题

近几年木糖醇作为新型的甜味剂正在悄悄地替蔗糖进入生活，在某温度下其溶解度分别为：30℃时70g，50℃时84个g，60℃时90g，如图表示的是木糖醇等固体的溶解度曲线．根据曲线判断下列说法错误的是（　　）

A．X为木糖醇的溶解度曲线

B．随着温度的升高，Z物质的溶解度逐渐减小

C．20℃时，X、Y、Z三种物质的饱和溶液中溶质质量分数最大的是Y

D．50℃时，Y、Z两物质的溶解度相等
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