天然吸尘器──青草有位园艺学家说：“要爱树、爱花，还得爱草。”这话是富有科学道理的。从５０年代以来，有许多经济发达的国家，都把种草种花看作是城市文明的重要标志之一，被人称为“花园之国”的新加坡，基本上实现了寸土必绿。德国的波恩，整个城市没有１平方米表... Natural cleaners ─ ─ Grass has a horticulturalist said: “To love the tree, love flowers, have to love grass.” This is a rich scientific truth. Since the 1950s, many economically developed countries have regarded the planting of grass and grasses as one of the most important symbols of urban civilization. Singapore, known as the “Garden Country,” has basically realized the necessary green. Bonn, Germany, the entire city does not have 1 square meter table ...