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问题 单项选择题 案例分析题

某单层工业厂房，厂房柱距12m，采用工字形截面的实腹式钢吊车梁。设置有两台Q＝25/10t的软钩桥式吊车，吊车每侧有两个车轮，轮距4m，最大轮压标准值Pk，max＝279.7kN，横行小车质量标准值Q1＝73.5kN，吊车轨道高度hR＝130mm。

假定吊车为重级工作制时，作用在每个车轮处的横向水平荷载标准值最接近于（）kN。

A.8.0

B.14.0

C.28.0

D.42.0

答案

参考答案：C

单项选择题

恒压过滤操作中（）。

A.滤饼厚度增加而阻力减小

B.滤饼厚度增加而推动力也增加

C.滤饼厚度和阻力都增加

D.滤饼厚度和阻力都不变
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单项选择题

Throughout the 19th century and into the 20th, citizens of the United States maintained a bias against big cities. Most lived on farms and in small towns and believed cities to be centres of (1) , crime, poverty and moral (2) Their distrust was caused, (3) , by a national ideology that (4) farming the greatest occupation and rural living (5) to urban living. This attitude (6) even as the number of urban dwellers increased and cities became an essential (7) of the national landscape. Gradually, economic reality overcame ideology. Thousands (8) the precarious (不稳定的) life on the farm for more secure and better paying jobs in the city. But when these people (9) from the countryside, they carried their fears and suspicions with them. These new urbanities, already convinced that cities were (10) with great problems, eagerly (11) the progressive reforms that promised to bring order out of the (12) of the city.

One of many reforms came (13) the area of public utilities. Water and sewerage systems were usually operated by (14) governments, but the gas and electric networks were privately owned. Reformers feared that the privately owned utility companies would (15) exorbitant (过渡的) rates for these essential services and (16) them only to people who could afford them. Some city and state governments responded by (17) the utility companies, but a number of cities began to supply these services themselves. (18) of these reforms argued that public ownership and regulation would (19) widespread access to these utilities and guarantee a (20) price.

16（）

A.distribute

B.deliver

C.transfer

D.transport
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