Labor force is defined as being the total number of people who are available to work and earn income.This definition includes everyone who is employed or seeking paid employment,so it includes employees and the self-employed.Labor is one of the country's resources which can be combined with other resources to produce the goods and services required by the community..
　　Though the size of the workforce relies greatly on the size of the total population,there are several other aspects 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 a 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 inadequate numbers of young people entering it to take place of 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 influences 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,finance 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 govemment has less money available to it or the workforce members have to be taxed more heavily.
　　1、The population which is top-heavy with older people poses a problem to _____.
　　A.the government
　　B.the economy
　　C.the workforce
　　D.all of the above
　　参考答案：D
　　参考解析：由末段可知old people过分增加，会给三方面造成影响：the govemment，the economy以及the workforce.
　　2、Labor force is composed of _____.
　　A.people who are available to work and earn income
　　B.self-employed people only
　　C.only those who are looking for an employment
　　D.only the employees
　　参考答案：A
　　参考解析：由文中首句对labor force的定义可知选A.
　　3、The conclusion which can be drawn safely from the second paragraph is that _____.
　　A.a population growth from natural increase leads to a greater proportion of the work-force
　　B.a large population does not necessarily mean a higher proportion of workforce
　　C.the larger the number of the aged in a population,the higher the proportion of the workforce
　　D.if the population has an evenly spreaded age distribution,the workforce will be lower
　　参考答案：B
　　参考解析：第二段主要论述age disrribution对于劳动力规模的影响。
　　4、The factor which does NOT influence the size of the worldorce is _____.
　　A.the size of population
　　B.age distribution of the population
　　C.national economy
　　D.natural increase
　　参考答案：C
　　参考解析：由第二、三段可知影响劳动力规模的因素有the size of population，age distribution of the population以及natural increase.
　　5、When a population is said to be aging,_____.
　　A.more people are retiring than people entering the workforce
　　B.the birth rate is growing'
　　C.there is an oversupply of workforce
　　D.young people outnumber old people
　　参考答案：A
　　参考解析：见第三段的第一句话。
　　参考译文
　　劳动力指的是能够进行工作并获取报酬的人的总数。这一定义包括所有已经有工作和寻找有偿职业的人，所以它包括雇员和个体经营者。劳动力是一个国家的资源之一，和其他资源结合后就可以提供社会所需要的商品和服务了。
　　尽管劳动力的数量很大程度上取决于国家的总人口数，但其他方面的因素也会对它造成影响。总人口的年龄分布对现有劳动力有显著影响。如果人口中有很大一部分是由于太年轻或太老而无法工作的人，可用劳动力的数量就要少于年龄分布均匀的人口。如果人口的自然增长速度过快，也就是说出生人数远远超过死亡人数，那么总人口数量增加而劳动力的比率则下降。
　　有时，一个国家的人口会被描述成老龄化的人口，这就是说出生率下降或者上升的速度都很缓慢，没有足够多的年轻人来填补退休劳动力的空缺。人口年龄分布因为老年人数量多而变得不均衡。所以，出生人口增长得过快或过缓，劳动力占总人口的比率都会下降。
　　人口年龄分布状况对经济有几个重要影响。如果人口正在老化，退休的人数增加的同时就业的人数却没有相应的增加，就会衍生出没有经济能力为退休人口提供适当社会服务的问题。如果老年人得在特定的福利院或是疗养院接受照顾，社会就必须为此提供经济支持。如果劳动力人数相对于总人口数较小，政府的税收也会相应较少，结果就是或者政府没有足够的钱为老年人提供福利，或者劳动者的税收负担加重。