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问题 单项选择题

用命令“INDEX ON姓名TAG index name UNIQUE"建立索引，其索引类型是______。

A．主索引

B．候选索引

C．普通索引

D．惟一索引

答案

参考答案：D

解析：[知识点] 表的索引：主索引，候选索引，普通索引，惟一索引[评析]该命令的含义是建立一个对“姓名”字段的索引项，索引名为“index name”，UNIQUE说明建立惟一索引。

单项选择题

Jack’s friend Tony had recently gotten a tattoo (纹身), and Jack was so impressed by Tony’s bravery and his tattoo that he decided to get one too. Why do a lot of young people in North America get tattoos today Peer pressure, media influence, and personal expression are some of the common reasons.
The desire to be part of a group, 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. For example, in one gang all the members may wear green army jackets and have large "Xs" tattooed on their arms. It is not only gangs that have this type of special "uniform". Young people often belong to a certain group of friends. Some of these groups wear only brand-name clothes. Others wear tattoos. When a person’s friends are all doing something, such as getting a tattoo, that person is more likely to do the same thing, and get a tattoo too.
The media is another big influence behind the popularity of tattoos in North America. A wide variety of media images show tattoos. Tattoos can be seen on people appearing in commercials selling expensive cars. Famous sports heroes with tattoos are shown in magazines. Fashion models are often seen in magazines and on TV 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.
It is not always the influence of other people or the media that results in a person getting a tattoo. 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. 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. Lovers may tattoo each others’ names over their hearts. A tattoo can be a public sign to show what is important in a person’s life.

Jack got a tattoo because of ______.

A. a desire to express himself
B. the influence of the media
C. the influence of friends
D. a desire to be fashionable
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问答题 简答题

为保证人身安全，作业人员下道避车的同时还应做到哪些？
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