1970年,法国农场的平均规模为19公顷。In 1970 the average size of a French farm was 19 hectares.他有将近1,000公顷的草场和耕地。He had nearly a thousand acres of grazing and arable land.每年都有几千公顷的森林遭到破坏。Thousands of hectares of forest are destroyed eac...
Man – made CFCs are the main cause of ozone depletion in the stratosphere.人造氯氟烃是臭氧层破坏的主因.The decomposition of chlorofluorocarbons ( CFCs ) has been a hot topic in recent years.氟里昂分解已成为当今环保技术的热点之一.CFCs cause depletion of ...