When my first wartime Christmas came, I

下图是初中化学常见的实验装置，请结合所学化学知识，回答有关问题：

(1)气体的制取装置：

①写出带有标号仪器的名称：a_____、b_____。

②用KClO和MnO₂制取O₂应选用的发生装置是：_______ （填序号，下同）；用稀硫酸和锌粒制取H₂应选用的收集装置是_________或E。

(2)气体的制取原理：①实验室用过氧化氢溶 液和二氧化锰混合制取氧气,其中二氧化锰起___________作用,请写出反应的化学方程式：___________，

②实验室制取二氧化碳的化学方程式为：____________。

(3)气体的净化：

①实验制取的O₂中含有水蒸气，若使用F装置对氧气进行干燥，则装置内放入的液体是_____________，气体应从 __________端（填字母“g”或“h”）通入。

②实 验室用 稀盐酸和锌粒反应制取的氢气中常常混有少量的HCl气体，为除去H₂中的HCl气体，F装置内放入的溶液是__________。

阅读理解。

     Facial expressions carry meaning that is determined by situations and relationships. For example, in

American culture (文化) the smile is in general an expression of pleasure. Yet it also has other uses. A

woman's smile at a police officer does not carry the same meaning as the smile she gives to a young child. A smile may show love or politeness. It can also hide true feelings. It often causes confusion (困惑)

across cultures. For example, many people in Russia smiling at strangers in public to be unusual and even

improper. Yet many Americans smile freely at strangers in public places (although this is less common in

big cities). Some Russians believe that Americans smile in the wrong places; some Americans believe that Russians don't smile enough. In Southeast Asian culture, a smile is frequently used to cover painful feelings. Vietnamese people may tell a sad story but end the story with a smile.

     Our faces show emotions (情感), but we should not attempt to "read" people from another culture as we would "read" someone from our own culture. The fact that members of one culture do not express

their emotions as openly as do members of another does not mean that they do not experience emotions.

Rather, there are cultural differences in the amount of facial expressions permitted. For example, in public

and in formal situations many Japanese do not show their emotions as freely as Americans do. When with

friends, Japanese and Americans seem to show their emotions similarly.

     It is difficult to generalize about Americans and facial expressiveness because of personal and cultural

differences in the United States. People from certain cultural backgrounds in the United States seem to be more facially expressive than others. The key is to try not to judge people whose ways of showing

emotion are different. If we judge according to our own cultural habits, we may make the mistake of

"reading" the other person incorrectly.

1. What does the smile usually mean in the U.S.?

A. Love.

B. Politeness.

C. Joy.

D. Thankfulness.

2. The author mentions the smile of the Vietnamese to prove that smile can ___ .

A. show friendliness to strangers

B. be used to hide true feelings

C. be used in the wrong places

D. show personal habits

3. What should we do before attempting to "read" people?

A. Learn about their relations with others.

B. Understand their cultural backgrounds.

C. Find out about their past experience.

D. Figure out what they will do next.

4. What would be the best title for the test?

A. Cultural Differences

B. Smiles and Relationship

C. Facial Expressiveness

D. Habits and Emotions

饲料安全

应用多巴胺治疗帕金森病，下列说法错误的是（）

A.对运动减少疗效较差

B.应用小剂量

C.尽可能推迟使用时间

D.最后与DA受体激动剂合用

E.对震颤和强直有效

分时操作系统采用—回—的方式处理用户的服务请求，允许多个用户联机地使用计算机。