智慧树慕课答案
1、单选题：
微型计算机系统主要由（ ）组成。
选项：
A: 微处理器，存储器，输入输出设备，I/O接口，软件系统
B: 微处理器，总线，存储器，输入输出设备，I/O接口
C: 微处理器，主机，存储器，输入输出设备
D: 微处理器，存储器，总线，I/O接口，输入输出设备，软件系统
答案: 【 微处理器，存储器，总线，I/O接口，输入输出设备，软件系统】点我阅读全文
1、单选题：
Which of the following is NOT written by Pearl Buck?
选项：
A: The Good Earth
B: East Wind West Wind
C: All Men Are Brothers
D: A House Divided
答案: 【 All Men Are Brothers】点我阅读全文
1、单选题：
Which of the following roads is called Mother Road?
选项：
A: Route 66
B: Route 50
C: Interstate 5
D: Interstate 95
答案: 【 Route 66 】点我阅读全文
1、单选题：
数控技术，是采用 ______ 对机电产品或设备进行控制的一种自动控制技术。
选项：
A: 机械信号
B: 液压信号
C: 电气信号
D: 数字信号
答案: 【 数字信号】点我阅读全文
1、单选题：
素描的分类
选项：
A: 写实性素描
B: 表现性素描
C: 写实性素描和表现性素描
D: 印象素描
答案: 【 写实性素描和表现性素描】点我阅读全文
1、单选题：
画组合体的三面投影图首先选择哪个投影图的投射方向？
选项：
A: 水平投影
B: 正面投影
C: 侧面投影
D: 都不是
答案: 【 正面投影】点我阅读全文
1、单选题：
产品的年产量被称为（ ）。
选项：
A: 生产类型
B: 生产纲领
C: 生产模式
D: 生产批量
答案: 【 生产纲领】点我阅读全文
1、多选题：
宏观经济学研究的主要问题包括（多选）
选项：
A: 经济增长
B: 经济周期
C: 经济波动
D: 收入分配
答案: 【 经济增长;
经济周期;
经济波动】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
1、单选题：
电视节目应该是什么？
选项：
A: 电视上策划的节目
B: 电视台录制的节目
C: 电视台或者影视制作公司录制的可供人们感知和理解的视听作品
D: 传播人们向上的节目
答案: 【 电视台或者影视制作公司录制的可供人们感知和理解的视听作品】点我阅读全文