2020-2021学年北师大版（2019）高一英语选择性必修Unit3Conservation(1)-Reading(1)课件

选择性必修一 Unit 3 Conservation (1) The Sixth Extinction Reading (1) Activate and share extinction Activate and share 1. What is extinction? Extinction is a situation in which something no longer exists. dinosaur Activate and share 2. How much do you know about extinction? ① How many times up to today has life on Earth almost died out? A. Once. B. Five times. C. More than 10 times. Activate and share ② About which percent of all species on Earth became extinct during the mass extinction known as the “Great Dying”? A. Less than 10%. B. Nearly 50%. C. More than 90%. Activate and share ③ What do scientists think will cause the next mass extinction? A. Human activity. B. Natural causes. C. Unknown reasons. Read and explore Read and explore Check the answers in the quiz. ① How many times up to today has life on Earth almost died out? A. Once. B. Five times. C. More than 10 times. Read and explore ② About which percent of all species on Earth became extinct during the mass extinction known as the “Great Dying”? A. Less than 10%. B. Nearly 50%. C. More than 90%. ③ What do scientists think will cause the next mass extinction? A. Human activity. B. Natural causes. C. Unknown reasons.   Read and explore Get the main idea of each paragraph. Para. 1: Para. 2: Para. 3: Para. 4: Background history of the sixth extinction Causes of the sixth extinction Effects of the sixth extinction What we can do to prevent the sixth extinction Read and explore Background history Causes Effects Solutions The Sixth Extinction Development of the passage Read and explore 2. Read the passage again and complete the notes. Meaning of extinction: Extinction The number of extinctions that have occurred so far: Two notable extinctions and their consequences: Main reasons that cause extinctions:How to avoid the sixth mass extinction: Read and explore Meaning of extinction: Extinctionentire species are wiped out Read and explore Extinction The number of extinctions that have occurred so far: over 90% of all species that ever lived Read and explore Extinction Two notable extinctions and their consequences: the third mass extinction killed 90% to 96% of all species; the fifth event, which occurred 66 million years ago, caused the death of dinosaurs. Read and explore Extinction Main reasons that cause extinctions: volcanic eruptions, asteroids hitting the Earth from space, changes in sea levels, the decrease of oxygen content of the sea, global warming Read and explore Extinction How to avoid the sixth mass extinction: change the way we live, including setting up special areas where plants and animals can be protected; change how we work and travel by using cleaner, more natural sources of energy; improve our farming methods Read and explore Retell this part of the passage according to your notes. Meaning of extinction: Extinction The number of extinctions that have occurred so far: Two notable extinctions and their consequences: Main reasons that cause extinctions:How to avoid the sixth mass extinction: Read and explore Retelling Extinction means the entire species are wiped out. So far over 90% of all species that ever lived are extinct. Along the history, there are 2 notable extinctions, the third one and the fifth one. During the third mass extinction, known as the “Great Dying”, 90% to 96% of all species died out. The fifth one, which occurred 66 million years ago, caused the death of dinosaurs. Read and explore Retelling There are many reasons that cause extinctions, such as volcanic eruptions, asteroids hitting the Earth from space, changes in sea levels, the decrease of oxygen content of the sea and global warming. Read and explore Retelling The good news is that we can do something to avoid the sixth mass extinction. Firstly, we have to significantly change the way we live. We need to take steps to save endangered species, including setting up special areas where plants and animals can be protected. Also, we can change how we work and travel by using cleaner and more natural sources of energy, such as wind and solar energy. We also need to improve our farming methods. Read and explore 3. Read the passage again and answer the questions. ① What did scientists find out in 2015? ② Why does the writer think the sixth mass extinction will come? ③ Why does the writer believe we’ll probably die out if 75% of the Earth’s species die out? ④ What did people do in the case study to protect black robins? Which claim(s) did the study support in the text? Read and explore ① What did scientists find out in 2015? The study looked at how quickly species die out due to natural causes, that is, the “background extinction rate”. They found that human activity is causing species to die out 1,000 times faster than normal. Read and explore ② Why does the writer think the sixth mass extinction will come? Because human activity has negatively affected all other species on Earth, including animals and plants. Read and explore ③ Why does the writer believe we’ll probably die out if 75% of the Earth’s species die out? Because our world and our lives depend on the balance in nature between animals and plants. Read and explore ④ What did people do in the case study to protect black robins? Which claim(s) did the study support in the text? Ø People protected Old Blue’s eggs, helped them to hatch, and took care of the chicks. People are restoring their habitats and removing pests like mice and cats from the islands where they live. Ø What we can do to prevent the sixth extinction Read and explore Causes Effects An example of protection The Sixth Extinction Retell this part of the passage. Read and explore The study in 2015 found that human activity is causing species to die out 1,000 times faster than normal. It is clear that human activity has negatively affected all other species on Earth, including animals and plants. Retelling Read and explore Retelling Read and explore Retelling The good news is that people are doing something to protect animals and plants on Earth. For example, people are taking measures to protect an endangered bird called Old Blue. Through our efforts, the number of this bird is increasing steadily. Therefore, you see, we can do something to help the earth and it’s never too late to act. Think and share l reduce waste l put rubbish into separate dustbins l cycle or take public transportation l use fewer plastic bags while going shopping Summary Background history Causes Effects Solutions The Sixth Extinction Homework Thank you!