Unit 1 Scientific DiscoveryText A Evolution and Natural SelectionText B Darwin's Observations and the Social Implications of DarwinismUnit 2 Science and LifeText A Cancer & ChemicalsText B Why Do My Allergies Change as I Age?Unit 3 A Better Life on EarthText A The End Is Not at HandText B China a Major Promoter of Global Poverty ReductionUnit 4 Scientists and Science CommunityText A The Man Who Discovered Mother NatureText B Building a Shared Future for All Life on Earth： China in Action．Unit 5 Society and PsychologyText A Laws of Lasting LoveText B You Are What You ThinkUnit 6 Types of PeopleText A I Am a HighbrowText B I Am a LowbrowUnit 7 Perspectives on LifeText A Two Truths to Live byText B Approach to LifeUnit 8 Love in a LifeText A This Was My MotherText B What Is a Great Book?Unit 9 Art： Past and PresentText A Art HistoryText B Modern ArtUnit 10 LiteratureText A The Story behind Dream of the Red ChamberText B Of Studies