Now our city becomes much greener. A lot of trees, grass and flowers were planted on both sides of the streets. There are a lot of advantages(好处) because of them. First, trees, grass and flowers can make our city more beautiful. Second, they can keep the air clean because they absorb carbon dioxide(吸收二氧化碳). Third, they can reduce(减少) the noise. Finally, trees can make the weather cool in summer and warm in winter. Then how to make our city greener? First, we should plant more trees, grass and flowers. Then, we should look after the planted trees, grass and flowers carefully.
