用英语回答：水污染的原因；如何保护水资源

In 21 century, water pollution is a big problem.
we all know water is important to us. but still, some people don't care about it, and keep polluting the water. they thought this will not affect them, but in fact, it does.
there are several ways that tell us how water get polluted.
1. polluted water came to the river from the factory.
2. people throw garbage in to the water.
3. garbage things from the factory polluted the water under ground.
4. oil come out from the boat....
to solve these problems, we need to make a plan. first, we need to know what cause the water pollution, it is the things i worte on the top. second, we should do something at home like: to tell our parent not waste water.....
then, we should do something that can effect other people around us. like to make a poster that tell how important water is....
after that, we should do something globally, like writer a letter and send it to newspaper office to let