(
课件网) Unit 3 n. a situation in which sth. no longer exists 灭绝, 消亡 To read and talk about conservation To read for general understanding To read for specific information and understand words in context To learn about and practise the adjectives and nouns To express solutions for environmental problems How much do you know about extinction 1 Choose the option based on your knowledge. 1 How many times up to today has life on Earth almost died out a Once. b Five times. c More than 10 times. 2 About what 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 a text about extinction. Then check your answers in Activity 1. 2 1 How many times up to today has life on Earth almost died out a Once. b Five times. c More than 10 times. 2 About what 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. When: about 440 million years ago Size of the Extinction: Up to 85% of all living species eliminated Suspected Cause or Causes: Continental drift and subsequent climate change When: about 365 million years ago Size of the Extinction: Nearly 80% of all living species eliminated Suspected Cause or Causes: Lack of oxygen in the oceans, quick cooling of air temperatures, volcanic eruptions and/or meteor (流星) strikes When: about 250 million years ago Size of the Extinction: An estimated 96% of all living species eliminated Suspected Cause or Causes: Unknown—possibly asteroid (小行星) strikes, volcanic activity, climate change, and microbes (微生物) When: about 200 million years ago Size of the Extinction: More than half of all living species eliminated Suspected Cause or Causes: Major volcanic activity with basalt (玄武岩) flooding, global climate change, and changing pH and sea levels of the oceans When: about 65 million years ago Size of the Extinction: Nearly 75% of all living species eliminated Suspected Cause or Causes: Extreme asteroid or meteor impact wipe out species a group of animals or plants whose members are similar and can breed together to produce young animals or plants to stop existing to destroy or remove pletely affecting or involving a large number of people or things to say or think that someone or something is responsible for something bad different from what is usual or normal mass Read and match. die out unusual blame affect endangered (of a young bird, fish, insect, etc.) to come out of an egg to make sb./sth. return to its former state or condition to produce a change in sb./sth. in danger of being harmed or lost of many different types to become or m ... ...
