Here I want to tell you some information about water.

    Water covers most of our planet. People can find it in oceans, lakes and rivers, and under the ground. Water moves in the environment by evaporation, condensation, and precipitation. The warm Sun helps water change into vapour and rise up into the sky. It is evaporation. The vapour in the air forms clouds in the sky. It is condensation. When the clouds get heavy enough, the water falls back to the ground as rain or snow. This is precipitation.

    Ocean water has too much salt in it. Much of the water travels far over the land. When it travels over the land, the water picks up salt from the rocks and soil. About 97.5% of the Earth's water is salty water. It is expensive to take salt out of the water.

    All people need clean water. They need it for drinking, for cooking, and for bathing. Some people in a village in South America did not have clean water. Their water was full of oil and dirty things. People there got sick when they drank the water. Other people heard about the problem. They sent empty water tanks (储水池) to the village. Rainwater fell into the tanks. Now the people in that village have the clean water.

    Imagine you are taking a walk on the beautiful beach. Just then, your feet step over something and you hear a crack (噼啪声) —an empty plastic bottle. Things like this are happening more often because of sea rubbish.

    Studies show that 80% of all the waste is from the land. The waste is mainly plastics (塑料制品) which are really hard to degrade (降解). So the rubbish will remain there for a long time. Some of the pollution is caused accidentally. For example, about 10,000 product-filled boxes are lost at sea every year from business ships. Sometimes people just throw things into the water from boats or land. Many large rubbish areas are formed in the North Pacific Ocean.

    Thankfully, the situation isn't ignored (忽视). Groups like the National Oceanic and Atmospheric Administration (NOAA) are taking action to help clean the sea. Since 2006,76 projects have cleared out 3,814 metric tons (公吨) of rubbish from the sea. Methods of rubbish cleaning include using machines to remove (移除) the waste away from the surface of sea water. Besides, special nets are set by the mouths of rivers to stop the rubbish before it reaches the sea. If everyone does his part, sea rubbish seems like a problem that can be solved.

    We live on the earth. We use the sea around us. What do we take from the ocean? And what do we give to it?

    We take fishes from the ocean—millions of kilograms of fish, every year, to feed millions of people. We take minerals (矿物) from the ocean. We can get salt by evaporating (蒸发) seawater. such as gold. Seaweed (海草) becomes food of many kinds—even candy and ice cream—as well as medicine. Believe it or not, fresh water is another gift from the sea. We can't drink ocean water. But ocean water becomes fresh water when the salts are removed. In the future, we will find ourselves depending more and more on fresh water from the sea.

    The sea gives us food, fertilizer, minerals, water and other gifts. What do we give the sea? We pollute the ocean all the time. Throwing waste into the ocean is killing off sea life. Yet as the world population grows, we may need the sea and its gifts more than ever.

    We are finally learning that if we destroy our sea, we might also destroy ourselves. Hopefully, it is not too late.