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Unit 1 Nature in the balance
　　Welcome to the unit
　　Reading
　　Grammar and usage
　　Integrated skills
　　Extended reading
　　Project
Unit 2 Natural disasters
　　Welcome to the unit
　　Reading
　　Grammar and usage
　　Integrated skills
　　Extended reading
　　Project
Unit 3 The world online
　　Welcome to the unit
　　Reading
　　Grammar and usage
　　Integrated skills
　　Extended reading
　　Project
Unit 4 Scientists who changed the world
　　Welcome to the unit
　　Reading
　　Grammar and usage
　　Integrated skills
　　Extended reading
　　Project