智慧树慕课答案
1、单选题：
1．国际商法调整的商事关系具有国际因素，下列关于国际因素的描述不准确的是( )。
选项：
A: 主体、客体和内容都必须具有国际因素
B: 商事交易的主体，一方、双方或多方具有不同国籍
C: 商事交易的主体，住所、营业所位于不同的国家
D: 商事关系所指向的标的位于另一国家
答案: 【 主体、客体和内容都必须具有国际因素】点我阅读全文
1、单选题：
计量经济学是下列哪门学科的分支学科（ ）。
选项：
A: 统计学
B: 数学
C: 经济学
D: 数理统计学
答案: 【 经济学 】点我阅读全文
1、单选题：
以下哪种假设不属于材料力学的基本假设（ ）。
选项：
A: 均匀性假设
B: 各向同性假设
C: 连续性假设
D: 线弹性假设
答案: 【 线弹性假设】点我阅读全文
1、多选题：
关于整本书阅读的特点，下列说法正确的有哪些？
选项：
A: 丰富了语文课程。
B: 只适合小学低年级开展。
C: 以略读、浏览为主。
D: 开展形式受制于读物内容。
答案: 【 丰富了语文课程。;
以略读、浏览为主。】点我阅读全文
1、单选题：
环境设施中的使用功能要服务于大众，主要适用于
选项：
A: 个人需求
B: 文化需求
C: 公共性需求
D: 审美需求
答案: 【 公共性需求】点我阅读全文
1、单选题：
以下哪项基本技术是学习网球技术最先需要掌握的？
选项：
A: 发球技术
B: 正手击球技术
C: 截击球技术
D: 反手技术
答案: 【 正手击球技术】点我阅读全文
1、单选题：
1、在以下各类消费者中，受心理因素影响程度最小的是（ ）。
选项：
A: 个体消费者
B: 家庭消费者
C: 组织消费者
D: 以上都不对
答案: 【 组织消费者】点我阅读全文
1、单选题：
下列观点中，不是描述操作系统的典型观点是（）
选项：
A: 操作系统是众多软件的集合
B: 操作系统是用户和计算机之间的接口
C: 操作系统是资源的管理者
D: 操作系统是虚拟机
答案: 【 操作系统是众多软件的集合】点我阅读全文
1、单选题：
PLC的实际应用中，哪些不属于开关量逻辑控制？
选项：
A: 注塑机控制
B: 电镀生产线
C: 电梯控制
D: 温度、压力、流量等连续变化的模拟量的闭环控制
答案: 【 温度、压力、流量等连续变化的模拟量的闭环控制】点我阅读全文
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