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专题〇 初识MATLAB

随堂测验

1、单选题：
‍MATLAB一词来自（      ）的缩写。‎
选项：
A: Mathematica Laboratory 
B: Matrix Laboratory
C: MathWorks Lab
D: Matrices Lab
答案: 【 Matrix Laboratory】点我阅读全文

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第一章 社会调查概述

第一章 单元测验

1、单选题：
‎了解和描述社会现象的状况，回答这种社会现象“是什么”，表明了社会调查具有（      ）‌‎‌
选项：
A: 描述功能
B: 解释功能
C: 预测功能
D: 研究功能
答案: 【 描述功能】点我阅读全文

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第1单元第1讲绪论主讲人王一凡

1化学的定义和主要分支

1、单选题：
‍1、化学的主要分支中，俗称的“四大化学”二级学科是‌
选项：
A: 无机化学、有机化学、分析化学和生物化学。
B: 无机化学、有机化学、物理化学和分析化学。 
C: 无机化学、有机化学、生物化学和高分子化学。
D: 不能确定。
答案: 【 无机化学、有机化学、物理化学和分析化学。 】点我阅读全文

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第一章中国人的饮食之道

中国人的饮食之道章节测试

1、单选题：
​中国人在过春节的时候，全家要聚在一起吃饺子， 因为饺子代表着（     ）。​​​​​​​
选项：
A: 长寿
B: 团圆
C: 喜庆
D: 好吃
答案: 【 团圆】点我阅读全文

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第一周第1章绪论

随堂检测

1、多选题：
‍与无机化合物相比较，有机化合物在性质上具有那些特点？‎‍‎
选项：
A: 组成简单，结构复杂，数目庞大
B: 多数有机物易燃烧，固体有机物熔点较低
C: 化学反应速率慢，且常伴有副反应
D: 大多数有机物难溶于水，易溶于有机溶剂
答案: 【 组成简单，结构复杂，数目庞大;
多数有机物易燃烧，固体有机物熔点较低;
化学反应速率慢，且常伴有副反应;
大多数有机物难溶于水，易溶于有机溶剂】点我阅读全文

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第二单元多任务处理

多任务处理 Multitasking

1、多选题：
What can we do to multi-task better in interpreting?‏
选项：
A: To make each sub-task routine or automatic by practice
B: To make the brain energy pool larger through great concentration
C: To allocate brain energy more effectively
D: No option here. Please select answers among A, B and C.
答案: 【 To make each sub-task routine or automatic by practice;
To make the brain energy pool larger through great concentration;
To allocate brain energy more effectively】点我阅读全文

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01 初识品牌

1.1 品牌是如何产生的？

1、单选题：
‏宝洁公司的第一个产品品牌是（）。​
选项：
A: 飘柔
B: 虎牌
C: 女神
D: 象牙皂
答案: 【 象牙皂】点我阅读全文

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第一章 医院和住院环境

第一章单元测验

1、单选题：
‎不属于候诊室护士工作范畴的是‌
选项：
A: 根据病情测量生命体征
B: 收集整理各种检验报告
C: 随时观察候诊者病情变化
D: 候诊者多时，协助医生诊治
答案: 【 候诊者多时，协助医生诊治】点我阅读全文

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单元1 3ds Max的基本操作

单元1 测试题

1、单选题：
‌3ds max 界面中，默认显示的四个视图是‍
选项：
A: 前视图、后视图、左视图、摄像机视图
B: 前视图、后视图、右视图、摄像机视图
C: 前视图、顶视图、左视图、透视视图
D: 前视图、顶视图、右视图、透视视图
答案: 【 前视图、顶视图、左视图、透视视图】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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