water is a useful source.nobody can live without water.water can make people live,the used water can use to watering plants,washing the rooms and so on.in rencet years ,the water resauce shortage,it is because of the humans destroy.they throw away the used thing anywhere they want,make the river so dirty.now,we must take measures to save water,we should recycling the water,do not throw the used things into the river or lake,besides ,we should call up more people take part in this activity to save water,what's important ,we should set an example to the little children.