人们在劳动之余,总喜欢到空气清新的公园里去休息……人们在晚饭之后,总喜欢到树木掩映的缘地上去漫步……这主要是因为树木能够形成安静,美好的环境,给人以清洁、舒畅和富有生气的感觉,对人的心理起调节和镇静作用。人离不开氧气。每个人每天大约需要零点七五公斤氧气,呼出零点四公斤二氧化碳。当空气中氧的含量由百分之二十一骤然降到百分之十时,人就会恶心呕吐。而空气中百分之六十的氧来源于森林绿地,因此,科学家把森林比为“绿色工厂”,这个“工厂”是一个制 People in the spare time, always like to go to the fresh air park to rest ... After dinner, people always like to wander through the tree-covered edge ... This is mainly because the trees can form a quiet, beautiful environment, giving With a clean, comfortable and full of feeling of life, the mentality of people from the regulation and sedation. People can not do without oxygen. Each person takes about 0.75 kg of oxygen daily and blows out 0.40 kg of carbon dioxide. When the oxygen content in the air drops sharply from 21% to 10%, people will vomit nausea and vomiting. While 60% of the oxygen in the air comes from forest green space. Therefore, scientists compare the forest to a “green factory,” which is a system