People in the United States in the
nineteenth century were haunted by the prospect that unprecedented change in the
nation’s economy would bring social chaos. In the years following 1820, after
several decades of relative stability, the economy entered a period of sustained
and extremely rapid growth that continued to the end of the nineteenth century.
Accompanying that growth was a structural change that featured increasing
economic diversification and a gradual shift in the nation’s labor force from
agriculture to manufacturing and other nonagricultural A. A highly conservative society that was resistant to new ideas. B. A society that was undergoing fundamental changes. C. A society that had been gradually changing since the early 1700’s. D. A nomadic society that was starting permanent settlements. [多选题]基站天线常用极化方式包括:
A.水平极化 B.垂直极化 C.-45°极化 D.+45°极化 [单选题]生产经营单位的安全生产规章制度所约束的对象是( )。
A.管理人员 B.主要负责人 C.所有从业人员 [判断题]电流互感器运行时二次回路严禁短路。
A.正确 B.错误 [填空题]管道(),内外温差(),烟囱效应越显著。
[多选题]依据《中国南方电网有限责任公司电力安全工作规程》,()等箱式配电设备宜设置验电和接地装置。
A.配电站 B.配电开关站 C.箱式变电站 D.电缆分接箱 [判断题]由于互感器要求的试验电源容量相对较小,因此只要有相应电压等级的试验变压器即可方便地进行该项试验。
A.正确 B.错误 [判断题](64978)( )机车使用串励牵引电机是因为串励电机的特性比较硬,不易空转。( )(2.0分)
A.正确 B.错误 [填空题]海绵剂通常分为两类:一是用()的海绵剂;二是用()的海绵剂。
[单选题]RS485端口在节点数为32个,配置了120Ω的终端电阻的情况下,驱动器至少还能输出电压(____)。
A.1.2V B.1.5V C.2.4V D.3.6V [单项选择]排除和输送温度超过80℃的空气或其它气体以及易燃碎屑的管道,与可燃或难燃物体之间应保持不小于()的间隙。
A. 150mm B. 200mm C. 250mm D. 400mm [判断题]在示波器垂直输入端附近的面板上通常标有一个电压值,如:400V,这个电压值表示该输入端可承受的最大直流加交流峰值电压。( )
A.正确 B.错误 [单选题]1分子葡萄糖无氧酵解时净生成几分子ATP
A.1 B.2 C.3 D.4 E.5 [多选题]反渗透系统利用反渗透膜的特性来去除水中绝大部分什么
A.可溶性盐 B.胶体 C.有机物 D.微生物 [判断题] 距离保护第一段的保护范围基本不受运行方式变化的影响 ( )
A.正确 B.错误 [判断题] 开关柜压力释放装置应无异常,释放入口无障碍物。
A.正确 B.错误 我来回答: 提交
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