题目

下列关于质点的认识正确的是（）A.研究原子时一定可以把原子看成质点B.研究地球的公转时，可以把地球看成质点C.研究汽车过桥时不能把汽车看成质点，但研究汽车从上海到北京的运动过程时，可以把汽车看成质点D.研究跳水运动员在空中的动作时，可以把运动员看成质点 答案：BC【试题分析】原子虽然很小，但我们在研究原子内部核外电子的运动时，很显然不能把原子看成质点；地球虽然很大，但其大小相对其公转轨道可忽略，故可看成质点；同一辆汽车，在过桥和长途旅行两种过程中，前者其大小不可忽略，而后者可忽略；运动员跳水时，我们欣赏的是他在空中的优美动阅读理解。     If you can speak English, you know a lot of English words. You can read, speak and understand. But there is another kind of language you need to know- the language of the body.      All over the world, people "talk" with their hands, with their heads and with their eyes. When Japanese people meet, they bow (鞠躬；弯腰).When Indians meet, they put their hands together. What do American and British people do?      Americans are more informal (不拘礼节的) than the British. They like to be friendly. They use first names, they ask questions and they talk easily about themselves. When they sit down, they like to relax in their chairs and make themselves comfortable.      British people are more reserved (矜持的, 缄默的). They take more time to make friends.They like to know you before they ask you something of your home.      When British and American people meet someone for the first time, they shake hands. They do not usually shake hands with people they know well. Women sometimes kiss their women friends, and men kiss women friends. When a man meets a man friend, he just smiles, and says"Hello".Men do not kiss each other, or hold hands. Even fathers and sons do not often kiss each other. 1. People can communicate with each other using ________. A. only words B. only body language C. only the English language D. not only words but also body language 2. We can learn from the passage that ________. A. handshake and kiss can not be used in greeting B. people can "talk" with their hands, heads and eyes C. only a few people use body language D. body language is more often used by people than words 3. British people take more time to make friends because ________. A. they are quite conservative (保守的) B. they don't like people to go to their homes C. they are not as friendly as the Americans D. they find it more interesting to stay alone 4. When Indians meet, they ________. A. kiss each other B. bow to each other C. put their hands together D. just smile 5. In the USA and British,  ________. A. men always kiss their women friends when they meet B. people would like to shake hands whenever they meet their friends C. women are more likely to kiss each other while men aren't D. fathers and sons often kiss each other