题目

青藏铁路路基两旁各插有一排碗口粗细、高约2m的铁棒（如图所示），我们叫它热棒。热棒在路基下还埋有5m深，整个棒体是中空的，里面灌有液氨。热棒的工作原理很简单：当路基温度上升时，液态氨受热发生  ①  ̲，上升到热棒的上端，通过散热片将热量传导给空气，气态氨由此冷却  ②  ̲变成了液态氨，又沉入了棒底。这样，热棒就相当于一个天然“制冷机”。请问文中空格处的物态变化名称是 A．①汽化 ②液化B．①液化 ②汽化C．①升华根据短文内容回答下列问题。 In a classroom in any country，the teacher teaches more than art or history or language．He or she teaches what is known as the “hidden course”-- the culture（文化）of that country．    In a society such as the United States，people with different history, culture and language join together and think highly of individualism(个人主义)．Their education as a part of the society(社会)，also think of this greatly．Teachers try to make each student special．Students do not have to remember a lot of information；instead，they work alone and find answers by themselves．There is often a discussion in the classroom．At an early age students learn to have their own ideas．Their education encourages personal thought．The importance is put on how to arrive at an answer and not simply to get the correct answer．    In most Asian countries，the people have the same languages，history, and culture．Perhaps for this reason，the education there shows society’s ideas in group goals rather than individualism．Children in China and Japan often work together and help each other on homework．In the classroom，the teacher often teaches in a public way．He says，and the students listen．There is not much discussion．Instead，the students repeat rules or information that they have been taught in order to keep them in mind．    In many ways these differences come from different educational psychology(教育心理学)．In Western countries teachers make it easier for the students to learn for themselves．In the Eastern，however, teachers often feel that their job is to pass knowledge to students，or the students can’t learn anything． 1．What is the “hidden course” according to the passage? 2．What do American teachers do in class? 3．What do Asian teachers do in class? 4．What’s the main difference in education between the East and the West? 5．What do you think the proper title for the passage is?