Trees reduce yearly heating and cooling costes by 2.1 billion dollars in the U.S.Trees provide wind protection and shade.One shade tree can keep a building up to 20 degrees cooler in the summer!是什么意思_Trees reduce yearly heating and cooling costes by 2.1 billion dollars in the U.S.Trees provide wind protection and shade.One shade tree can keep a building up to 20 degrees cooler in the summer!在线翻译_英语_读音_用法_例句