智慧树慕课答案
1、多选题：
下列关于蒸馏的操作错误的是？
选项：
A: 加热速度宜慢，不能快，避免局部过热。
B: 蒸馏瓶的大小需根据待蒸液体的量而定。通常瓶内溶液上限不超过瓶容积的2/3，而对于下限不做要求。
C: 为了防止爆沸，加热前应加入一勺沸石。
D: 蒸馏装置不能漏气，接引管部分应与大气相通，不能使装置成密闭系统。
答案: 【 蒸馏瓶的大小需根据待蒸液体的量而定。通常瓶内溶液上限不超过瓶容积的2/3，而对于下限不做要求。;
为了防止爆沸，加热前应加入一勺沸石。】点我阅读全文
1、单选题：
《晉靈公不君》一文中，身份為史官的人物是
选项：
A: 宣子
B: 提彌明
C: 靈輒
D: 董狐
答案: 【 董狐】点我阅读全文
1、填空题：
随堂测验:请举一个你注意到的近几年依靠创新快速崛起的产品或企业的例子（MOOC内容之外的例子）
答案: 【 答案不唯一。如江小白、香飘飘奶茶、1点点、华为、OPPO、vivo、海底捞等。】点我阅读全文
1、单选题：
最早颁布的VHDL的标准版本是（ ）.
选项：
A: IEEE-1076
B: IEEE-1074
C: IEEE-1075
D: IEEE-1078
答案: 【 IEEE-1076】点我阅读全文
1、单选题：
从国家和政府的文件、决议、指示、行动和领导人讲话这一来源渠道获取的新闻线索，可以制作的新闻属于
选项：
A: 时政新闻
B: 政策解读型新闻
C: 政府与领导人新闻
D: 时政类新闻、解读型新闻、社会问题报道等
答案: 【 时政类新闻、解读型新闻、社会问题报道等】点我阅读全文
1、单选题：
下列化合物中，不是有机化合物的是（ ）
选项：
A: 叶绿素
B: 氯仿
C: 尿素
D: 氨气
答案: 【 氨气】点我阅读全文
1、单选题：
( )是指人们没有得到满足的一种感受状态。
选项：
A: 愿望
B: 需求
C: 需要
D: 愿望
答案: 【 需要】点我阅读全文
1、判断题：
计算机只能处理由人们编写的、解决某些问题的、事先存储在计算机存储器中的二进制指令序列。
选项：
A: 正确
B: 错误
答案: 【 正确】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：
遗传学研究的重点内容是？
选项：
A: 动植物形态与分类
B: 细胞结构与功能
C: 遗传与变异
D: 核酸与蛋白质结构
答案: 【 遗传与变异】点我阅读全文