人教版九年级英语第十三单元知识点总结Unit13.Were trying to save the manatees!1 单词litter bottom fisherman coal ugly advantage cost wooden plastic takeaway bin shark fin cruel harmful be harmful to at the top of chain the food chain ecosystem industry law scientific take part in afford turn off reusable pay for take action transportation recycle napkin throw away put sth to good use pull.down upside gate bottle president inspiration iron work metal bring back creativity二1.现在进行时定义：表示说话时（瞬间）正在进行的动作，也表示
