UNIT 3 Section Ⅱ　Understanding the Text -【创新思维】2022-2023学年新教材高中英语选择性必修第一册同步导学案（北师大版）

SectionⅡ Understanding the Text _____________北那英语选择性必修第一册 ·必备知识通课文 –BIBEIZH/SHI TOWGKEWEW Part1LESSON1 课文助读┐ Extinctions”，where entire species are wiped out are not unusual^°in our Earth's history.In fact，over90percent of all species that ever lived are now extinct.In the last500million years，there have been five times when life on Earth has almost endedThese include the third mass∘extinction，known as the“Great Dying” 必备知识通课文质量评估提能力课时作业知能提升 ____________北英语选择性必修第一册 which killed 90% to 96% of all species.And the fifth event, which occurred° 66 million years ago, caused the death of the dinosaurs. The reasons for extinctions are varied. According to scientists, they include volcanic eruptions, asteroids hitting the Earth from space, changes in sea levels, the decrease of the oxygen content of the sea and global warming . Many scientists say we are now entering the Earth's sixth mass extinction. This time, human activity will be to blame. 必备知识 通课文 质量评估 提能力课时作业知能提升 北师英语选择性必修第一册 [读文清障] ①extinction n.灭绝 ②species/'spi:i:z/n.物种，种 ③unusual/Anju:3ue/ad.异常的；不平常的 ④in/over/during the last/past500 million years在过去的5亿年里 介词短语in/over/during the last/past...years常与现在完成时连用。 ⑤mass/mes/ad.大量的 必备知识 通课文 质量评估 提能力 课时作业 知能提升 北师英语选择性必修第一册 ⑥occur vi.发生 ⑦asteroid/'esterord/n.小行星 必备知识通课文 质量评估提能力 课时作业知能提升 北师英语选择性必修第一册 [句式评析] where entire species are wiped out,是where引导的非限制性定语从 句，对extinctions进行补充说明。 there have/has been..time(s)when.是固定句式，意为“已 经…”，when引导定语从句。 known as the“Great Dying”为过去分词短语作定语，修饰 extinction,相当于which was known as..o 必备知识通课文 质量评估 提能力 课时作业 知能提升 北师英语选择性必修第一册 which引导非限制性定语从句，补充说明the third mass extinction。 include后接五个并列的宾语，其中asteroids hitting the Earth from space是动词-ing形式复合结构作宾语。 必备知识通课文 质量评估提能力 课时作业知能提升 北师英语选择性必修第一册 Although it is not unusual for species to die out naturally,the rate at which this is now happening is cause for concern.A 2015 study by scientists who were based at Brown University and Duke University in the US,looked at how quickly species die out due to natural