植树种草，绿化环境，是我国人民千百年来的优良传统。民间素有“树木花草栽庭院，空气新鲜人舒展”的说法。科学实验证明，绿化能调节空气中的二氧化碳浓度。由于人和动物的呼吸，以及越来越多的煤炭、石油等含碳有机物的燃烧，导致空气中二氧化碳含量不断增加，严重威协人体 Planting trees and grass, greening the environment, is the fine tradition of our people for thousands of years. Folk known as “trees and flowers planted courtyard, air fresh people stretch” argument. Scientific experiments show that green can regulate the concentration of carbon dioxide in the air. Due to the respiration of humans and animals, and the increasing combustion of carbon-containing organic substances such as coal and petroleum, the carbon dioxide content in the air is constantly increasing,