Unit 13 We are trying to save the earth.知识点及练习Section A知识点1. try v. 试图，努力，尝试 用法：try to do sth. 尽力做某事 try doing sth. 尝试做某事try ones best (to do sth.) = do ones best (to do sth.) 尽某人最大的努力(做某事) 短语：try on 试穿 try out 试用，参加选拔 have a try 尝试，试一下 let me try 让我试一下2.the earth 地球，表示世界上独一无二的事物前面要加定冠词the。短语：on the earth 在地球上 on earth 究竟，到底3. pollution n.污染，污染物 pollute v. 污染 polluted adj.被污染的短语：air pollution 大气污染，空气污染 noise pollution 噪音污染 wate
