You without doubt sleep every day, but do you have a dream every night? How much do you know about dreaming? “Sleep are 1 than dream. We all need to dream.” some scientists say.

Dreams take up about one quarter of our sleeping time. People have several dreams every night. Dreams are like short films. They are usually in color. Some dreams are like old films. They come to us over and over again. That 2 because the dreamer is worrying about something. Sometimes dreaming is a way of trying to find an answer.

Some people get 3about their work from dreams. They may have been thinking about their work all day. These thoughts can carry into dreams.

Sometimes we4with a good feeling from a dream. But often we can't remember the dream.Dreams can disappear quickly from memory.

­5dreaming can be harmful. The more we sleep, the longer we dream. The mind is hard at work when we dream. That is why we may have a long sleep and still feel tired.

    I like pandas very much. They are very 1. Many of them live in Sichuan, 2. Pandas are beautiful animals. They are white and 3. They have big bodies(身体), 4sometimes they can also be quick. Pandas like to eat bamboo 5. They also like to sleep.

    Sometimes pandas go to other countries(其他国家). People there6 like pandas very much.

    There are not many pandas in the world. Now people know they are 7danger. They hope to help pandas 8 a good life. My uncle works in a panda center. It's9to go to the center. I can 10 many cute pandas there.

    Each one of us shares this planet with seven billion others. And we all need 1. People and products need to move from city to city and country to country. However, we all know 2 most cars, motorcycles, boats and planes cause air pollution. They are also 3.This is a serious problem in many cities.4 inventors are coming up with creative ideas to try to reduce the pollution and noise.

    In many cities around the world, motorcycles are very 5. Now Vietnam has around 33 million motorcycles and China has almost 120 million. Motorcycles are a faster and cheaper way to get around a city than 6. Yet air pollution is a growing problem. In large cities, people7it is difficult to breathe. To solve these problems, a US company designed an environmentally friendly motorcycle. It uses electricity as fuel (燃料). As a result, there is 8 pollution. It's also quiet and fast. This makes 9 a good choice for getting around a city.

    The Italian city of Venice is a city with only a few 10. There are no cars in the city center,11 cars, water taxis and buses carry people along the city's canals (运河). However, they cause pollution, 12 to the water. English engineers Dick and Jim designed a solar –powered(太阳能) water taxi. The water taxi 13 run for a day after being recharged(重新充电). Planes also cause air and noise pollution. Designing an environmentally friendly airplane is a real 14. Some airplane companies have 15 to solve the problems. Swiss engineers have gone one step further. They developed a solar airplane. This plane holds the world record for the longest solar-powered flight-1,541 kilometers from Arizona to Texas in America.