Ｌｏｏｋｉｎｇ Ｆｏｒｗａｒｄ ｔｏ ａｎ Ｅｃｏｌｏｇｉｃａｌ Ｃｉｖｉｌｉｚａｔｉｏｎ

ＰＡＮ　ＹＵＥ

HISTORICAL records showthat human beings haveexperienced three stagesof civilization．First．theprimitive Stone Age，which lasted formillious of years and saw peoplelivingin groups and relying on simple laborlike fishing and hunting．Next came theagricultural age，which lasted for about10,000 years．Peoples ability to changenature improved dramatically with theinvention Of iron tools．The third stagewas industrial civilization．which start-ed in 18th-century Britain and saw theformation of modern urban lifestyles．