Unit Sixteen Following the Fashion Unit Seventeen Job-hopping Unit Eighteen Retirement Unit Nineteen Euthanasia Unit Twenty Capital Punishment Unit Twenty-one Single-sex Education Unit Twenty-two Test-oriented Education and Quality-oriented Education Unit Twenty-three Private School and Public School Unit Twenty-four Economic Development and Environmental Protection Unit Twenty-five Human Cloning Unit Twenty-six Nature and Nurture Unit Twenty-seven Gun-possession Unit Twenty-eight Nuclear Energy Unit Twenty-nine Competition and Cooperation Unit Thirty Economic Globalization Appendix Ⅰ Reference Answers Appendix Ⅱ English Speech Evaluation Criteria of American Students Appendix Ⅲ Debate Topics