问题 单项选择题

负荷计算的目的是( )。

A.电气负荷是供配电设计所依据的基础资料,通常电气负荷是随时变动的
B.确定设计各阶段中选择和校验供配电系统及其各个元件所需的各项负荷数据
C.计算负荷是一个假想的、在一定时间间隔中的持续负荷,它在该时间间隔中产生的特定效应与实际变动负荷的效应相等
D.计算负荷通常按其用途分类(见3.1.2)。不同用途的计算负荷应选取不同的负荷效应及其持续时间,并采用不同的计算原则和方法,从而得出不同的计算结果

答案

参考答案:B

解析: 《工业与民用配电设计手册》第3版或《复习指导书(供配电)》3.1.1。

阅读理解

Jack lay, quiet and unmoving, for thirty minutes while a stranger repeatedly stabbed(刺) him with sharp needles, causing blood to pour steadily out of his leg. Jack was getting a tattoo. His friend Tony had recently gotten a tattoo, and Jack was so impressed by it that he decided to get one too. Peer pressure, media influence, and personal expression are some of the common reasons for wearing tattoos today.

The desire to be accepted by one’s friends or peers can have a great influence on what a person does. Sometimes, wearing a tattoo can be a sign that you belong to a certain group. Gangs often use special clothes and tattoos to identify their particular group. Some of these groups wear only brand-name clothes. Others wear tattoos. When a person’s friends are all doing something, that person is more likely to do the same thing.

The media is another big influence behind the popularity of tattoos in North America. A wide variety of media images show tattoos—people appearing in commercials selling expensive cars, famous sports heroes with tattoos in magazines, fashion models wearing designer clothes that show their bodies tattooed with detailed and colorful patterns. These media images link tattoos to ideas of wealth, success, and status. As a result, many people decide to get a tattoo for its fashion and status value.

Many people decide to wear tattoos in order to express their artistic nature, their beliefs, or their feelings-in other words, to show their individuality(个性). A musician in a rock band may get a tattoo of a guitar on the arm. Some environmentalists may tattoo pictures of endangered animals on their shoulders. A tattoo can be a public sign to show what is important in a person’s life.

As you can see, there are many reasons why young North Americans get tattoos. A tattoo can be part of a group’s uniform, a sign of fashion, or an expression of individuality. The decision to get a tattoo is most often a result of the influence of friends or media or the desire to express oneself. For Jack, it was a mixture of all three.

小题1:Jack has got tattoos in order to ________.

A.show his great bravery

B.gain a special experience

C.make himself more healthy

D.be different from others小题2:According to the passage, media images are linked to ________.

A.traditional lifestyle

B.social position

C.cultural background

D.public interest小题3:We can infer from the passage that ________.

A.some people get tattoos out of pressure

B.tattoo is related to religious belief

C.getting tattoos costs a lot of money

D.most people with tattoos are artists

判断题