( ) Although the world is hungry, it is even thirstier. While nearly 3/4 of the earth is covered with water, we are still short of drinking water. This is because about 97% of the water on the earth is sea water. So we can’t use it for watering plants or drinking directly. Humans can only drink and use fresh water from places including rivers, lakes and underground.
( ) How can we avoid a serious water shortage? First, we should save water and not waste it. Second, we should protect our water resources and not pollute them. Third, we should discover ways to reuse water. Scientists have made some progress in this field. Today, some large cities are reusing their water. But people’s need for water is increasing day by day. We still don’t have enough water. What else can we do?
( ) The sea seems to have the best answer. There is plenty of water in the sea. But we need to take the salt away from the sea water. This is very expensive. If scientists can find cheaper ways to do it, we can solve the problem of the shortage of water.