问题 问答题 简答题

简述白血病的实验室检查。

答案

参考答案:

①血象:白细胞总数增多或正常、减少;出现原始、幼稚细胞(急性白血病原、幼细胞多达10%~90%;慢性白血病依具体疾病类型而不同);红细胞、血红蛋白、血小板不同程度减少(在慢性粒细胞白血病的慢性期血小板可升高)。

②骨髓象:有核细胞增生明显或极度活跃,正常造血细胞受抑制。急性白血病:原始或早幼细胞大量增生(30%~90%以上)。慢性白血病:中、晚幼或成熟细胞增生为主,原始细胞多<10%。

单项选择题
单项选择题

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