There are a lot of colors in the worldThere are green grass,red sunny day, little white sheep, golden wheat, yellow star....In so many colors, my favourite color is blue, because the sky is blue, the deep sea is blue. How lovely the blue is!But know, the sky is not blue anymore, the waste gas from the factory and the car exhaust make the sky looks not blue, the sea is not blue with garbage pollution.The world is turning gray, we must do something! We should plant more trees, we shouldn’t leave rubbish everywhere and spit in public places. We must try our best to protect the earth. The world will become much more beautiful and sky will become more and more blue , Our life will be better and better.Let’s get to it!