本期我们学习环境相关的词汇~ 
1. erode /ɪ'rəʊd/
v. 使侵蚀;使腐蚀;使风化
e.g. Crashing waves have eroded the cliffs along the beach. 
e.g. The shoreline has eroded badly.
n. erosion /ɪ'rəʊʒ(ə)n/
听力11-4-4: Carbon-rich soil is dark, crumbly and fertile, and retains some water. But erosion can occur if the soil is dry, which is a likely effect if it contains inadequate amounts of carbon.
题目：Erosion is more likely in soil that is ______________
答案：dry.
注意erode 和 corrode 的区别
erode: “to gradually destroy, reduce, or wear down, by abrasion such as the action of wind and water on rocks.  更侧重于机械物理性腐蚀，如气候、水冲刷
corrode: “to gradually destroy or weaken, through chemical reaction, such as with rust or acid” 更侧重化学性腐蚀 
e.g. The metal roof of the building was corroding from years of acid rain.
注：acid rain 酸雨
2.dispose /dɪˈspoʊz/
 [phrasal verb] dispose of (something) 丢弃；扔掉
e.g. The agency has put an end to new efforts to dispose of hazardous waste in sensitive environmental areas.
注：hazardous  adj.有危害的
n. disposal 处理
e.g. waste disposal 废物处理
adj. disposable 用后即可丢弃的;一次性的
如：disposable food containers/chopsticks 一次性餐盒/筷子
可以反复使用的：reusable  
口语话题P2：Describe a time when you saw a lot of plastic waste.
e.g. The beach was littered with disposable food containers, plastic bottles and scraps. 
注：be littered with 充满的；
3. landfill /'læn(d)fɪl/
n. 垃圾填埋场；垃圾堆填区
e.g. 90 percent of American rubbish is dumped in landfill sites.
听力5-4-4：Recycling reduces greenhouse gas emissions from landfill sites and incineration plants.
注：incineration plants 焚烧场
4. discharge /dɪs'tʃɑːdʒ/
v. 排出;使流出; （液体,气体,废料等）
e.g. The oil that was discharged into the sea seriously harmed a lot of birds and animals.
e.g. Smokestacks from the factory discharge chemicals into the air.
注：smokestack (工厂、船舶等的）大烟囱
排放的废气多用: emission / waste gas 
排放的废水: effluent / waste water 
e.g. greenhouse gas emission 温室气体的排放
e.g. sewage effluent 下水道污物