Making cities greener has many advantages. First, it can make our air cleaner. Some researchers have proved that trees can reduce the amount of carbon dioxide in the atmosphere through absorption. Second, it
12,居民点 settlement;13,城市(城镇) city 镇 town市域 administrative region of a city 城市化 urbanization城市化水平 urbanization level城市群 agglomeration城镇体系 urban system卫星城(卫星城镇) satellite town