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第一章 单元测试

1、单选题：
（ ）是全国首个也是目前唯一一个共同富裕示范区。
选项：
A:江苏
B:广东
C:山东
D:浙江
答案: 【浙江】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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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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第三章血液的组成及理化特性

测试四

1、单选题：
‎贫血（红细胞减少）时，血液的粘滞性（ ）‍
选项：
A: 先增加后减少
B: 无明显变化
C: 增加
D: 降低
答案: 【 降低】点我阅读全文

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第一章昆虫的外部形态

第一章昆虫的外部形态

1、单选题：
‍刺吸式口器的喙由（  ）变来的。‍
选项：
A: 下唇
B: 上颚 
C: 下颚
D: 上唇
答案: 【 下唇】点我阅读全文

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第一周流体及其物理性质

单元测验

1、单选题：
​一个物体微元的变形大小与所受切应力相关，这个物体可以是：        ‍
选项：
A: 刚体
B: 弹性体
C: 流体
D: 无
答案: 【 弹性体】点我阅读全文

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第一章静力学公理和物体的受力分析

第一章测验

1、单选题：
‏两个力，它们的大小相等、方向相反和作用线沿同一直线。这是       ‌
选项：
A: 它们作用在物体系统上，使之处于平衡的必要和充分条件；
B: 它们作用在刚体系统上，使之处于平衡的必要和充分条件；
C: 它们作用在刚体上，使之处于平衡的必要条件，但不是充分条件；
D: 它们作用在变形体上，使之处于平衡的必要条件，但不是充分条件。
答案: 【 它们作用在变形体上，使之处于平衡的必要条件，但不是充分条件。】点我阅读全文

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第一章 课程概述

1-1 经典动画短片赏析概述 测试

1、单选题：
‎1、动画艺术的核心是？‌
选项：
A: 镜头语言
B: “动”
C: 画面                                  
D: 色彩
答案: 【 “动”】点我阅读全文

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第一章 绪论、教育及其本质

教育及其本质

1、单选题：
5.     ____________的提出标志着在教育起源问题上开始向科学解释转变。 （  ）‍A．神话起源说  B．生物起源说  C．心理起源说  D．劳动起源说‍​‍
选项：
A: A
B: B
C: C
D: D
答案: 【 B】点我阅读全文

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第一章心理学是什么

第一章心理学是什么单元测验

1、单选题：
​心理学的研究对象是_____‎
选项：
A: 人类
B: 动物
C: 人类和动物
D: 以上都不对
答案: 【 人类和动物】点我阅读全文

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