The earth moves round the sun, and the moon goes round the earth. When our part（部分） of the earth turns to the sun, it is day, When our part of the earth turns away from the sun, it is night. The sun is much bigger than the moon. But sometimes the moon looks bigger than the sun, because it's much nearer to the earth. The sun is very bright. It gives a very strong light. The moon looks quite bright, too. But it doesn't give any light at all. The moon looks much bigger and brighter than the stars .But actually（事实上）, the stars are much bigger and brighter than the moon. They look smaller than the moon because they're much farther away from us.

    Clean water is not only important for people to produce food, but necessary for our life However, many people in Asia and Africa don't have enough clean water to use The World Health Organization reports that almost 4 000 children die each day of dirty water or lack(缺乏)of water.

    Farmers use 70% - 85% 0f the world freshwater to produce food. People usually don't pay much attention to how much water industry(工业)uses, but you may be surprised to know that industry uses 59% of the water in developed countries.

    Home use takes up（占据）only 8% in the world. But as cities grow, more water will be used. The local government has to try to make people useless water. In 60% of European cities, people are saving water by using less. They even keep waste water for other use. In Australia, the government has encouraged people to collect rainwater and recycle water from showers for a second use, The US Environmental Protection Agency has made a water saving program to encourage families and businesses to check their water use and save more water. Scientists and the UN are looking for good water management as the key to solving the problem. We can all work together to protect our fresh water in our daily life.

    You don't have to be a weatherman to tell people about the weather. If you notice the animals, the sky and the world around, you can predict weather on your own.

    Examine the moon or sun, but do not look at the sun directl or it will hurt your eyes seriously. If you see a ring around the sun or moon, then warm weather follows. A golden ring around the moon warns us that a storm is on the way. A watery yellow sunset is a sign that rain may be near. Feel the direction of the wind. A wind blowing from the east shows that a storm will probably happen. A wind from the west means a sunny day. Monitor the clouds. There are three things about clouds you should look for: movement, color, and change. As a rule , the higher the clouds, the better the weather.  And the lower the clouds , the worse the weather will be.

    The rainbow has a message, too. If you see the sun in the east and a rainbow in the west, the rain may be coming your way. If the sun is in the west and the rainbow is in the east, the rain will be moving away from you. Look at your shoes as you walk through the grass in the morning. If the grass is wet with dew (露珠), then you can expect dry weather. But if the grass is dry, then it will be wise of you to take your umbrella.

    Have you ever stood beside the ocean and stared at the waves (波浪)? The way they move is changing! Nothing is more peaceful than watching the movement of water.

    Every ocean has waves. Unless you are lucky enough to live by the sea, though, you probably can't watch the waves very often. How would you like to have your own wave machine? Making one is easy and a lot of fun.

    Now that you have made your ocean, put your bottle on its side. Wait a minute. The water win be on the bottom. The oil and paint thinner mixture will be on the top. Now tip (倾斜) the bottle back and forth (反复来回) and watch the waves.

    Do you still get free plastic bags from the supermarkets? Things have changed.

    China has banned(禁止) free plastic bags at shops and supermarkets, and people have to pay for using plastic bags. The rule started on 1st June. It came because our country tried to make litter less. Making super­thin(超薄的)plastic bags has also been banned.

    The Chinese once used about 3 billion plastic shopping bags a day, and they have caused pollution of the environment. The bags have become a main cause of plastic pollution because they are easy to break and people throw them away here and there. So the Chinese people are encouraged to bring their own bags for shopping.

    What kind of shopping bag is the best to bring? Some students in Chongqing have a good idea. They make their own shopping bags. They use old clothes to make cloth bags(布袋), and send them to their parents as presents. They also ask their parents and friends to use cloth bags instead of plastic ones. They think it is their duty to protect the environment.