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问题 判断题

电力系统谐波产生的原因是由于电力系统中某些设备和负荷的非线性特性，当正弦波（基波）电压施加到非线性负载上时，负载吸收的电流与其上施加的电压波形不一致，导致电流发生了畸变。（）

答案

参考答案：对

单项选择题 共用题干题

System analysis is traditionally done top-down using structured analysis based on (1). Object-oriented analysis focuses on creation ofmodels. The three types of the analysis model are (2). There are two substages of object-oriented analysis. (3) focuses on real-world things whose semantics the application captures. The object constructed in the requirement analysis shows the (4) of the real-world system and organizes it into workable pieces. (5) addresses the computer aspects of the application that are visible to users. The objects are those which can be expected to vary from time to time quite rapidly.

空白（4）处应选择（）

A.static structure

B.system components

C.data flows

D.program procedures
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单项选择题

公路工程交工验收由( )主持。

A．县、市级以上交通主管部门

B．县、市级以上质量监督站

C．建设单位

D．监理单位
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