Unit 3 Travel journal【单元导航】The LancangMekong RiverThe LancangMekong River is an important international river in Southeast Asia，which flows through six countries.The Lancang River is rich in natural resources and wildlife.The largest part of the basin is a natural conservation area for rare and endangered animals and plants in China.The basin area is still an underdeveloped region at present.However，due to deforestation (滥伐森林) and pollution from industrial ， agricultural and domestic sectors ， the water quality of the river has been deteriorating (恶化) in recent years.In this paper，the author analyzed the present water quality status of the Lancang River both on the mainstream and its tributaries (支流) based on the data of 1990～1997.The results have shown that the water quality status of the river is not good enough although there are few industrial estates in the region.The pollutants in the river are mainly organic (有机的) materials.The main pollution sources are wastewater from paper plants，sugar plants，domestic wastewater from Dali City and Jinghong City ，as well as，fertilizers and chemicals from agricultural fields.Heavy metals from the Lanping Lead and Zinc Mine and the Lancang Lead Mine are the main pollutants in the tributaries of the Bijiang River and the Nanla River.Water quality of the mainstream is better than its tributaries；it better in the dry season than in the wet season.Section One Warming Up and ReadingⅠ.Leadin1.回答下列问题 (1)Do you like travelling? (2)Where have you been? (3)Can you tell your partner something about it?2.假设你有 4 天的假期，与你的同桌讨论一下你可能去的地方，讨论内容要包括： Where are you going on holiday? When are you leaving? How are you going to...? ...
