题目内容
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 (21) effect on the available workforce. If the population has a high (22) of very young people or of (23) too old to work, then the available workforce would be lower than (24) there were an (25) spread age distribution. If the population grows raidly (26) natural increase, i.e., the number of births greatly (27) the number of deaths, then as a total population increases the proportion of the workforce (28) .Sometimes a population is described as aging, (29) means that the birth rate is either falling or growing very slowly, and as people retire (30) the workforce there are insufficient numbers of young people entering it to (31) those who are leaving it. The population is top heavy with older people. So the (32) of the population in the workforce declines when there is (33) 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 (34) a corresponding increase in the number entering the workforce, this raises the problem of the ability of the economy to provide a (35) level of social services to the retired group. If the (36) are to be cared (37) in special homes or hotels, finance must be (38) for that purpose. If the size of the workforce is small relative (39) 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 (40) more heavily. 25().
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In the atmosphere, carbon dioxide acts rather like a one-mirror-the glass in the roof of a greenhouse which allows the sun’s rays to enter but prevents the heat from escaping.According to a weather expert’s prediction, the atmosphere will be 3℃ warmer in the year 2050 than it is today, if man continues to burn fuels at the present rate. If this warming up took place, the ice caps in the poles would begin to melt, thus raising sea level several meters and severely flooding coastal cities. Also the increase in atmospheric temperature would lead to great changes in the climate of the northern hemisphere, possibly resulting in an alteration of the earth’s chief food-growing zones.In the past, concern about a man-made warming of the earth has concentrated on the Arctic because the Antarctic is much colder and has a much thicker ice sheet. But the weather experts are now paying more attention to West Antarctic, which may be affected by only a few degrees of warming: in other words, by a warming on the scale that will possibly take place in the next fifty years from the burning of fuels.Satellite pictures show that large areas of Antarcitic ice are already disappearing. The evidence available suggests that a warming takes place. This fits the theory that carbon dioxide warms the earth.However, most of the fuel is burnt in the northern hemisphere, where temperatures seem to falling. Scientists conclude, therefore, that up to now natural influences on the weather have exceeded those caused by man. The question is: Which natural cause has the most effect on the weatherOn possibility is the variable behavior of the sun. Astronomers at one research station have studied the hot spots and "cold" spots (that is, the relatively less hot spots) on the sun. As the sun rotated, every 27.5 days, it presents hotter of "colder" face to the earth, and different aspects to different parts of the earth. This seems to have a considerable effect on the distribution of the earth’s atmospheric pressure, and consequently on wind circulation. The sun is also variable over a long term: its heat output goes up and down in cycles, the latest trend being downward.Scientists are now finding mutual relations between models of solar-weather interactions and the actual climate over many thousands of years, including the last Ice Age. The problem is that the models are predicting that the world should be entering new Ice Age and it is not. One way of solving this theoretical difficulty is to assume a way of thousands of years while the solar effects overcome the inertia (惯性的) of the earth’s climate. If this is right, the warming effect of carbon dioxide might thus be serving a useful counter-balance to the sun’s diminishing heat. On the basis of their models, scientists are of the opinion that ().
安徽的齐云山是我国丹霞地貌中最高的山地。( )
[案例三] 背景 某公路工程所需的主要建材有路基土方填料、砂石材料、水泥、沥青材料、沥青混合料和钢材等。所有材料均由项目部自己采购和组织运输。项目部材料采购部门拟按工程量清单、材料供应计划、材料用量计划、材料用款计划、材料采购计划的顺序进行材料计划管理，并对几种材料的主要工程指标及工程特性提出了如下要求(摘要)：(1)对于碎石提出了可松散性要求；(2)为区分砂的粗细度，提出了砂的平均密度和湿度要求；(3)对于水泥提出了针入度的要求。 该项目在施工过程中，项目部有关部门通过资料分析，发现混凝土工程的实际成本比计划成本增加较多，主要原因是砂、碎石材料成本的增加。但有关资料表明，砂、碎石的购入原价与施工预算时的价格一致。 在工程施工中还发生了如下事件。 事件一：水泥混凝土结构局部出现了蜂窝、麻面，项目部认为并未影响结构，因此未做任何处理。 事件二：在满堂支架桥梁施工中，发生了支架垮塌，造成直接经济损失40万元。项目部在事后的第5天向上级公司进行了汇报。 事件三：在路基施工放样时，由于工期紧，项目部新购了一台全站仪后立即投入使用，并将一台超过规定周检确认时间间隔的仪器也投入使用，使路基工程按时完工。 问题： 逐条判断对材料工程指标及工程特性要求是否合理请说明理由。
[案例二] 背景 某单位承担了某道路工程项目的施工任务。由于该项目周边环境繁杂，施工干扰大，为了确保道路工程项目的施工质量，该施工单位根据有关文件和资料对该公路工程质量控制设置了关键点，该工程在实施中发生如下事件。 事件一：该工程技术总负责人负责对技术文件、报告、报表进行审核和分析。 事件二：由于第三方的原因，该工程被迫停工。停工时项目经理组织有关人员对其质量进行了检查，均合格。该工程在停工20d后复工，项目经理在未经检查的情况下指示继续施工。 事件三：在某关键工序施工完毕后，由施工人员对其质量进行自检，达到合格标准，紧接着便开始下道工序的施工。 问题： 工程技术总负责人负责对技术文件、报告、报表进行审核和分析是否妥当如不妥，应由谁负责
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