Waste can bring a lot of problems. Although China is rich in some resources (资源) , we are short of others, for example, fresh water. It is reported that we will have no coal or oil to use in 100 years. So if we go on wasting our resources, what can we use in the future and where can we move? Think about it. I think we should say no to the students who waste things every day. Everyone should stop wasting as soon as possible.
In our everyday life, we can do many things to prevent (阻止) waste from happening, for example, turn off the water taps when we finish washing, turn off the lights when we leave the classroom, try not to order more food than we need, and so on. Little by little, everything will be changed. Waste can be stopped one day, if we do our best.