mooc答案类别

1绪论

1绪论

1、单选题：
‍ 公共事业的特征是什么‍‍‍
选项：
A:  公共性、公益性、非物质性、非营利性
B: 公共性、劳务性、非物质性、非营利性
C: 公共性、公益性、发展性、非营利性
D: 公共性、阶级性、劳务性、非营利性
答案: 【  公共性、公益性、非物质性、非营利性】点我阅读全文

本文共有 101 人阅读

第1周——初识C语言从认识变量和常量开始

codeblocks介绍——从Hello World开始

1、单选题：
‌#include <stdio.h>是‎
选项：
A: 编译预处理指令
B: 语句
C: 函数
D: 程序入口
答案: 【 编译预处理指令】点我阅读全文

本文共有 104 人阅读

1.实验室安全知识

实验室安全知识

1、单选题：
​对危险废物的容器和包装物以及收集、贮存、运输、处置危险废物的设施、场所，必须：‍
选项：
A: 设置危险废物识别标志
B: 设置识别标志
C: 设置生活垃圾识别标志
D: 不用设置任何标志
答案: 【 设置危险废物识别标志】点我阅读全文

本文共有 148 人阅读

Lesson 2

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

本文共有 137 人阅读

第一单元云计算概论

第一单元测验

1、单选题：
1. ‎云计算是对（‎D‎）技术的发展与运用‎ ‎‍云计算是对（    ）技术的发展与运用。‎
选项：
A: 并行计算
B: 网格计算
C: 分布式计算
D: 三个选项都是
答案: 【 三个选项都是】点我阅读全文

本文共有 114 人阅读

课程概况

绪论随堂测

1、单选题：
​关于“物料衡算”，下列说法正确的是（    ）。​
选项：
A: 物料衡算不适用于化学变化过程
B: 物料衡算是质量守恒定律的一种具体表现形式
C: 物料衡算就是输入和输出的物料的流量相等
D: 物料衡算就是输入和输出的物料的流速相等
答案: 【 物料衡算是质量守恒定律的一种具体表现形式】点我阅读全文

本文共有 116 人阅读

课程概况

绪论随堂测

1、单选题：
‏关于“物料衡算”，下列说法正确的是（    ）。‎
选项：
A: 物料衡算不适用于化学变化过程
B: 物料衡算是质量守恒定律的一种具体表现形式
C: 物料衡算就是输入和输出的物料的流量相等
D: 物料衡算就是输入和输出的物料的流速相等
答案: 【 物料衡算是质量守恒定律的一种具体表现形式】点我阅读全文

本文共有 107 人阅读

第1章绪论

第1章单元测验

1、单选题：
‎在数据库系统中DBMS（数据库管理系统）的位置是处于哪里？‏
选项：
A: 应用系统和应用开发工具之间
B: 应用开发工具和操作系统之间 
C: 操作系统和数据库之间
D: 不知道
答案: 【 应用开发工具和操作系统之间 】点我阅读全文

本文共有 108 人阅读