根据如图信息所作出的判断,错误的是( ) A.氯原子的核电荷数为17 B.钠的原

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问题:

根据如图信息所作出的判断,错误的是(  )

A.氯原子的核电荷数为17

B.钠的原子结构示意图中X=8

C.一个氯原子的质量为35.45g

D.在化学反应中,钠原子容易失去1个电子

考点:原子结构示意图原子结构原子的定义离子结构示意图元素周期表
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一个粉笔盒的体积约是1(    )。

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患者,女,71岁,全牙列缺失,曾戴过全口义齿,自诉上全口固位较差,下颌尚可。口腔检查发现上、下颌弓关系正常,上颌牙槽嵴吸收较多。重新进行全口义齿修复。

为加强上全口固位需作上颌后堤沟,后堤沟位于

A.前颤动线处

B.后颤动线处

C.软、硬腭之间

D.腭小凹与两侧翼上颌切迹连线后约2mm处

E.腭小凹与上颁结节连线后1mm处

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下列关于民族三原则的说法不正确的是

A.民族平等是实现民族团结的政治基础

B.民族平等是处理民族问题的根本原则

C.各民族共同繁荣是民族平等和民族团结的物质保障

D.民族平等和民族团结是共同繁荣的前提条件

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轫致辐射

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Internet is a vast network of computers that connects many of the world’s businesses, institutions, and individuals. (46) The Internet, which means interconnected network of networks, links tens of thousands of smaller computer networks. These networks transmit huge amounts of information in the form of words, images, and sounds.

The Internet has information on every topic.(47)Network users can search through sources ranging from vast databases to small electronic" bulletin boards", where users form discussion groups around common interests. Much of the Internet’s traffic consists of messages sent from one computer user to another. These messages are called electronic mail or e-mail. Internet users have electronic addresses that allow them to send and receive e-mail. Other uses of the network include obtaining news, joining electronic debates, and playing electronic games.(48)One feature of the Internet, known as the World Wide Web, provides graphics, audio, and video to enhance the information in its documents. These documents cover a vast number of topics.

People usually access the Internet with a device called a modem. Modems connect computers to the network through telephone lines. Much of the Internet operates through worldwide telephone networks of fiber-optic cables(49) These cables contain hair-thin strands of glass that carry data as pulses of light. They can transmit thousands of times more data than local phone lines, most of which consist of copper wires.

In the future, the internet will probably grow more sophisticated as computer technology becomes more powerful. (50)Many experts believe the Internet may become part of a larger network called the information superhighway. This network, still under development, would link computers with telephone companies, cable television stations, and other communication systems. People could bank, shop, watch TV, and perform many other activities through the network.

(49) These cables contain hair-thin strands of glass that carry data as pulses of light. They can transmit thousands of times more data than local phone lines, most of which consist of copper wires.

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