桑白皮除泻肺平喘功效外，具有的功效是（） A.降逆止呕 B.燥湿化痰 C.利

微电脑全自动洗衣机电脑发出排水指令后，其内部立即开始计时，并不断将计时时间与（）进行比较。

A.基准时间常数

B.通电时间

C.断电时间

D.排水时间

阅读下列材料：

材料一：第一届世博会于1851年在英国伦敦举办，在展会期间，最受参观者瞩目的是如下新产品：

图一
图二
图三

材料二：如图四，自由女神的右手高举着火炬，左手拿着一部文献《独立宣言》。

材料三：经过漫长的航行后，他和同伴于1492年10月12日突然发现远处有陆地，于是高兴地前往，到了近处一看，原来是座海岛，这个岛就是现在美洲加勒比海上巴哈马群岛中的瓜纳哈尼岛。500多年前的这一大壮举打破了美洲大陆与世隔绝的状态，1992年为纪念发现美洲大陆500周年。结合所学知识回答问题：（1）写出材料一1851年的世博会英国有可能展出的先进工业展品。____________________________________________________________________________________________（2）材料二中“自由女神像”左手执的《独立宣言》对美国有什么意义？

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（3）材料三中谈到“纪念发现美洲大陆500周年”，是谁发现了美洲大陆？

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（4）说说你对上海世博会的认识。

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骨折常见的移位方式有（）。

A.成角移位

B.侧方移位

C.短缩移位

D.分离移位

E.旋转移位

内存条安装时，一般不用注意安插方向。

Workforce is defined as the total number of people who are available to work and earn incomes. The definition includes everyone who is employed or seeking paid employment, so it includes employers and the self-employed.

Although the size of the workforce depends a great deal on the size of the total population, there are several other influences which also affect it. The age distribution of the total population has a very marked effect on the available workforce. If the population has a high proportion of very young people or of those too old to work, then the available workforce would be lower than if there were an evenly spread age distribution. If the population grows rapidly from natural increase, i.e., the number of births greatly exceeds the number of deaths, then as the total population increases, the proportion in the workforce declines

Sometimes a population is described as aging, which means that the birth rate is either falling or growing very slowly, and as people retire from the workforce, there are not enough young people entering it to replace those who are leaving it. The population is top-heavy with older people. So the percentage of the population in the workforce declines when there is either a rapid increase in births or a falling birth rate.

The age distribution of the population has several important effects on the economy. If the population is aging and there is an increase in the number of people retiring without a corresponding increase in the number entering the workforce, this raises the problem of the ability of the economy to provide a reasonable level of social services to the retired group. If the aged are to be cared for in special homes or hotels, finances must be available for that purpose. If the size of the workforce is small relative to the total population, then the government tax receipts are relatively low and either the government has less money available to it or the workforce members have to be taxed more heavily.

It can be concluded from Paragraph 2 that ().

A. a population growth leads to a greater proportion of workforce

B. a large population does not necessarily mean a high proportion of workforce

C. the size of the aged determines the proportion of workforce

D. the proportion of the very young determines the size of workforce