初一口语题：用英语回答问题回答问题（不是翻译）：How to keep water clean?Give out one example.

Good environment can make people feel happy. To improve the environment means to qualify our life . What should we do to improve our environment ?
We should plant more trees . And we should prevent those factories from pouring waste water into rivers , lakes and fields . Whenever we see litter on the ground , we should pick it up and throw it into a dustbin . Don’t spit in public places . Don’t draw on public walls . It’s our duty to keep our earth clean and tidy
The importance of water
Of all the things we eat and drink, water is the most important. We can live without food for many days, but two or three days without water, usually makes people die.
However, not all of people understand this. They keep throwing rubbish into the rivers or lakes . Some factories even pour waste water into the river. As a result, many rivers and lakes have become so dirty that the water is no longer safe for people to drink .
Let’s do our best to keep the water clean to save ourselves .

十八、Water
Water is very important for our life. Every day we use water to drink, too cook and to wash. Water is necessary for all plants. They need water to grow. People can’t live without water. Plants will die without water. It is important to all living things. However, many people pollute lakes and rivers with waste water, so we must stop some people or some factories from wasting water or polluting water and help keep the water clean. At the same time we should save as much water as possible.

Do not pour waste water into river.