Try to find the main idea sentence in each paragraph and write them down. 识别每段主题句并抄录原句。 1. London’s weather is very strange. It can rain several times a day; each time the rain may come suddenly after the sun is shining brightly. The air is damp and chill right through July. On one march afternoon on Hampton Heath last year it rained three times. There was one hail storm, and the sun shone brilliantly — all this within two hours’ time. It is not unusual to see men and women rushing down the street on a sunny morning with umbrellas on their arms. No one knows what the nest few moments will bring. 2. Just as I settle down to read or watch television he demands that I play with him. If I get a telephone call, he screams in the background or knocks something over. I always have to hang up to find out what’s wrong with him. Baby-sitting with my little brother is no fun. He refuses to let me eat a snack in peace. Usually he wants half of whatever I have to eat. Then, when he finally grows tired, it takes about an hour for him to all asleep. 3. Doctors are of the opinion that most people cannot live beyond 100 years, but a growing number of scientists believe that the aging process can be controlled. There are more than 12000 Americans over 100 years old, and their numbers are increasing each year. Dr. James Langley of Chicago claims that theoretically and under ideal conditions, animals, including man, can live six times longer than their normal period of growth. A person’s period of growth lasts about 25 years. If Dr. Langley’s theory is accurate, future generations can expect a life span of 150 years. 4. Good manners are important in all countries, but ways of expressing good manners are different from country to country. Americans eat with knives and forks; Japanese eat with chopsticks. Americans say “Hi” when they meet; Japanese bow. Many American men open doors for women; Japanese men do not. On the surface, it appears that good manners in America are not good manners in Japan , and in a way this is true. But in any country, the only manners that are important are those involving one person’s behavior toward another person. In all countries it is good manners to behave considerately toward others and bad manners not to. It is only the way of behaving politely that differs from country to country.