地绿,需要花、草、树木的打扮;天蓝,必须清除粉尘、烟雾的遮掩。地绿天蓝有利于人类的健康和生存,优美的环境能使人减少疾病的发生而延年益寿。人要接触空气,而空气中含有大量的微生物,这些微生物主要来自飞扬的灰尘。在一般城市,每公顷地面仅烟尘一项的降落量,每年就在3吨左右,大工业城市的数量就更大。这些微生物中不仅有多种 Green, need flowers, grass, trees dress; sky blue, you must clear the dust, smoke cover. Green sky blue is conducive to human health and survival, beautiful environment can make people reduce the incidence of diseases and prolong life. People come into contact with the air, and the air contains a large number of microorganisms, these microorganisms mainly from flying dust. In general cities, the amount of dust and soot per hectare is only about 3 tons a year, and the number of large industrial cities is even larger. There are not only many of these microorganisms