Unit5 A Delicate World Starting Out 课件-2024-2025学年高中英语外研版（2019）选择性必修第二册

Unit 5 A Delicate World Look at the bottom picture in page 49 What can you see? I can see bare ground with trees cut down and almost no grass. What will happen in such a place? There will be some disasters, like soil erosion, drought, desertification... easily destroyed Vocabulary in Video 1. ecosystem 2. biodiversity 3. once in a while 4. go extinct 5. satellite 6. delicate 灭绝 生态系统 偶尔 生物多样性 脆弱的 卫星 Connected together Activity 1: Watch a video and think the following questions: 1. Are humans part of Earth’s ecosystems? Why? 2. In what ways can humans affect ecosystems? Yes. Humans are part of Earth’s ecosystems. Because all the living things live in ecosystems and people are living things. Humans can affect ecosystems in positive and negative ways. For example, to have a positive influence on ecosystems, people can plant trees, feed and protect animals, recycle things, etc. However, deforestation, air and water pollution and excessive waste affect ecosystems in a negative way. ___________ 失败做某事 _______________ 与…和谐相处 _________________ 对…产生兴趣 _______________ 被引入 ___________ 土壤流失 New Phrases of the Unit: fail to do in harmony with develop an appetite for soil erosion be introduced to New Phrases of the Unit: ___________ 失控 ___________ 从…移除 _______________ 从…减少到… _____________ 因此，结果 ___________ 结果是，证明是 turn out in consequence decrease from...to remove from out of control ____________________ 大量的 ____________________ 一劳永逸的 ____________________ 每一个 ____________________ 做……是有必要的 ____________________ 与……共存 New Phrases of the Unit: a substantial number of once and for all every last coexist with owe it to ...to do Activity 2: Look at the satellite images and answer the questions. What is happening to the area according to the satellite images? What do you think a later satellite image would show? Aral Sea is becoming smaller and smaller / shrinking. 3.What do you think caused these changes? Maybe it's due to over exploitation; or human over exploitation. The water area may disappear. Why is Aral Sea shrinking? In the 1960s, people built dams on the two rivers so that they could irrigate the surrounding desert region and focus on cotton production. As a result, the Aral Sea has been decreasing in size, and by 1997, it had shrunk to a tenth of its original size, splitting into four lakes. By 2009, the south-eastern lake had disappeared altogether, and the south-western lake had been reduced to a thin strip, with a salinity level of more than 110 grammes per litre. Introduction of Aral Sea (死海) Situated in Central Asia, Aral Sea was once the world’s fourth largest body of inland water. It was famous for its thriving fishing and tourism industry which contributed a lot to the local economy. As it was the most salty sea in the world, contained 10 grammes of salt per litre, people who were not able to swim can easily float on the sea. Activity 3: What do you know about Aral Sea? What happened after the sea shrank? The shrinking of the Aral Sea became known as “one of the planet's worst environmental disasters”. After the sea shrank: 1. water disappeared → less tourists came→ tourism decline→ unemployment 2. water disappeared → water was saltier→fish and sea animals died→ the fish industry declined→ unemployment What happened after the sea shrank? After the sea shrank: 3. the water disappeared→ more salt was left on the seabed→ extra salt spread to other areas→ environment got worse 4. the water disappeared→ seabed became dry land→ local weather became hotter and drier→ living environment got worse Final result: The decline of the once-thriving fishing industry brings unemployment and economic hardship to the surrounding region. How can human being protect Aral sea? 1. Plant more trees or grass to keep the soil. 2. Hire more cleaners to pick up the garbage near the sea. 3. The country should do more propaganda to encourage the citizens protect the envrionment. 4. Build some man-made rivers to drain(引流) nearby rivers , so that more water will be fed into the Aral Sea. How can human being protect Aral sea? Thank you for watching! $$