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第七周带传动2

传动总论和带传动单元测试

1、单选题：
‍由带传动、圆柱齿轮传动、直齿锥齿轮传动和链传动组成的某多级平行轴传动系统,(  )宜放在高速级。‌
选项：
A: 带传动
B: 链传动
C: 圆柱齿轮传动 
D: 直齿锥齿轮传动
答案: 【 带传动】点我阅读全文

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第一章 学校音乐教育基本理论

1.2 《义务教育音乐课程标准》简介

1、单选题：
​《义务教育音乐课程标准（实验稿）》是什么时候颁布的？‌
选项：
A: 2000年
B: 1999年
C: 2001年
D: 2008年
答案: 【 2001年】点我阅读全文

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ChapterFifteenOpinion

QuizonChapterFifteen

1、多选题：
‍Which of the following terms fit the scope of a feature? (applicable to feature stories about news events)‏
选项：
A: inclusiveness
B: panorama
C: integrity
D: episode of an event
E: enlarged close-ups
答案: 【 episode of an event;
enlarged close-ups】点我阅读全文

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第1周 从一间书屋说起数据库背景与知识准备

我做好知识准备了吗？

1、单选题：
‍数据库系统投入使用后，负责管理和维护、确保数据库安全和系统运行正常的人员或团队是（）。​
选项：
A: DBA
B: 系统分析员
C: 应用程序员
D: 终端用户
答案: 【 DBA】点我阅读全文

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1 汉字的文化属性

1.汉字的文化属性--单元测验

1、单选题：
‍以下能说明汉字表意属性的是？​
选项：
A: 蛛：左边的虫字旁表字义和昆虫有关，右边的朱为声旁
B: 燕：下边的“灬”说明这个字跟水有关系
C: 照：“照”字由“日”、“刀”、“口”、“灬”组成
D: 姑：姑妈不等于姑娘
答案: 【 蛛：左边的虫字旁表字义和昆虫有关，右边的朱为声旁】点我阅读全文

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第1章数字逻辑概论

数字逻辑概论测验题

1、单选题：
‍将二进制数(101101.11)B转换成十进制数是        ‌
选项：
A: 45.3
B: 45.75
C: 46.75
D: 48.75
答案: 【 45.75】点我阅读全文

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第一章常用开发工具使用简介

第一章单元测验

1、单选题：
window系统中，使用Sublime工具，要生成如下html标签形式，应如何书写emmet语法‍<div>div1</div>‍<div>div2</div>‍<div>div3</div>‍‎‍
选项：
A: div{div$}*3
B: div{$div}*3
C: div*3{$div}
D: div*3{div$}
答案: 【 div{div$}*3】点我阅读全文

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第2周计算

小测验

1、填空题：
写出以下代码执行后，t1和t2的值，以空格隔开：‏int a=14;‏int t1 = a++;‏int t2 = ++a;‏
答案: 【 14 16】点我阅读全文

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Lesson2

Scanning

1、单选题：
​Read the passage "The Discovery of X-rays" quickly and choose the paragraph(s) which contain(s) the answer(s). You may choose more than one answer for question 3. ​​​The Discovery of X-rays​​ ​Par. 1 Except for a brief description of the Compton effect, and a few other remarks, we have postponed the discussion of X-rays until the present chapter because it is particularly convenient to treat X-ray spectra after treating optical spectra. Although this ordering may have given the reader a distorted impression of the historical importance of X-rays, this impression will be corrected shortly as we describe the crucial role played by X-rays in the development of modern physics.​Par. 2 X-rays were discovered in 1895 by Roentgen while studying the phenomena of gaseous discharge. Using a cathode ray tube with a high voltage of several tens of kilovolts, he noticed that salts of barium would fluoresce when brought near the tube, although nothing visible was emitted by the tube. This effect persisted when the tube was wrapped with a layer of black cardboard. Roentgen soon established that the agency responsible for the fluorescence originated at the point at which the stream of energetic electrons struck the glass wall of the tube. Because of its unknown nature, he gave this agency the name X-rays. He found that X-rays could manifest themselves by darkening wrapped photographic plates, discharging charged electroscopes, as well as by causing fluorescence in a number of different substances. He also found that X-rays can penetrate considerable thicknesses of materials of low atomic number, whereas substances of high atomic number are relatively opaque. Roentgen took the first steps in identifying the nature of X-rays by using a system of slits to show that (1) they travel in straight lines, and that (2) they are uncharged, because they are not deflected by electric or magnetic fields.​Par. 3 The discovery of X-rays aroused the interest of all physicists, and many joined in the investigation of their properties. In 1899 Haga and Wind performed a single slit diffraction experiment with X-rays which showed that (3) X-rays are a wave motion phenomenon, and, from the size of the diffraction pattern, their wavelength could be estimated to be 10-8 cm. In 1906 Barkla proved that (4) the waves are transverse by showing that they can be polarized by scattering from many materials.​Par. 4 There is, of course, no longer anything unknown about the nature of X-rays. They are electromagnetic radiation of exactly the same nature as visible light, except that their wavelength is several orders of magnitude shorter. This conclusion follows from comparing properties 1 through 4 with the similar properties of visible light, but it was actually postulated by Thomson several years before all these properties were known. Thomson argued that X-rays are electromagnetic radiation because such radiation would be expected to be emitted from the point at which the electrons strike the wall of a cathode ray tube. At this point, the electrons suffer very violent accelerations in coming to a stop and, according to classical electromagnetic theory, all accelerated charged particles emit electromagnetic radiations. We shall see later that this explanation of the production of X-rays is at least partially correct.​Par. 5 In common with other electromagnetic radiations, X-rays exhibit particle-like aspects as well as wave-like aspects. The reader will recall that the Compton effect, which is one of the most convincing demonstrations of the existence of quanta, was originally observed with electromagnetic radiation in the X-ray region of wavelengths.​​​​When were X-rays discovered?​
选项：
A: Par. 1
B: Par. 2
C: Par. 3
D: Par. 4
E: Par. 5
答案: 【 Par. 2】点我阅读全文

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1. 初探组件化的软件世界

第1章测验

1、单选题：
‏以下不属于组件技术框架的是？‎
选项：
A: EJB
B: COM
C: ASP
D: CORBA
答案: 【 ASP】点我阅读全文

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