下列物质中，属于纯净物的是（ ） A．石油 B．矿泉水 C．烧碱 D．天然气

简单评述美国华盛顿特区中心区规划结构。

在光电效应实验中，先使用某种频率的单色光a作为光源，再换用频率更大、光强更小的单色光b．将两次实验得到的光电流与电压的关系作在同一坐标纸上，下列图象中正确的是（　　）

A．

B．

C．

D．

患者一旦发生心源性哮喘，迅速采取的护理措施是()

A．安排转入监护病房

B．准备好止喘药物氨茶碱

C．给予乙醇湿化高流量给氧

D．患者两腿下垂

E．尽快补充由气喘丧失的水分

Every year, whenever Spring Festival arrives, a lot of Chinese people cannot wait to go home. They queue for long hours in front of the ticket offices in railway stations, or do whatever they can in order to get a ticket. They tolerate the long journey on the train only to want to ______ with their near and dear ones.

According to The Beijing Youth Daily, most Chinese celebrate the Spring Festival not only because they want to follow tradition, there are also some practical reasons to explain Chinese people's fever for the holiday. Compared with one's workplace, home provides a more humane environment for one to relax oneself.

Society may do with or without you, but at home, you become unique and indispensable. You may be the father or mother, daughter or son, grandfather or grandmother in the family and the family will be incomplete if anyone is absent, because every member in the family is bound together, and everyone in the family is pleased with the feeling that he or she is unique and irreplaceable.

In addition, family provides an ideal environment for one to fully relax oneself. At home, one can take one's time do whatever he or she wants, and one can spend money whenever one likes. In society, however, one needs to do everything fast and with high efficiency, because society always reqiores efficiency and maximum profits. Such company principles make people merely a tool in modern society.

Chinese people's strong desire for Spring Festival shows that they feel oppressed and have a sense of predicament(困境) of existence in modern society. The Spring Festival provides a chance for them to escape from such anxiety and treasure the long-lost tradition of community spirit. With the Spring Festival, people can find back the warm, family atmosphere often seen in days gone by.

1. What's the passage mainly talking about? (Please answer within 10 words. )

2. Fill in the blanks with proper words or phrases to complete the sentence. (Please answer within 10 words. )

3. Which sentence in the passage can be replaced by the following one?You may not be a necessary part in society, but in your family, you are very important and no one else can take the place of you.

4. Do you think home is important for Chinese to celebrate the Spring Festival?Why or why not? (Please answer within 30 words. )

5. Translate the underlined sentence in the last paragraph into Chinese.

教师资格与教师资格制度