Unit 1: Collapse Unit 2: Beyond Earth Unit 3: Health and Genes Unit 4: Vanishing Cities Unit 5: Eco-Living Unit 6: Wildlife in Trouble Unit 7: Human Body Unit 8: Social Behavior Unit 9: Creativity Unit 10: Elements and Toxins Unit 11: Islam and the West Unit 12: Wealth and Finance
Bruce Rogers taught ESL and test preparation courses at the Economics Institute at the University of Colorado, USA, since 1979. He has also taught in special programs in Indonesia, Vietnam, Korea, the Czech Republic, and Egypt. In addition to this series, he is the author of Introductory Guide to the TOEIC Test and The Complete Guide to TOEIC Test, both with National Geographic Learning. David Bohlke has over 25 years of experience as a teacher, teacher trainer, program director, editor, and materials writer. He has taught in universities, high schools, language institutes in Japan, Korea, Saudi Arabia, and Morocco, and has conducted multiple teacher-training workshops in Asia, the Middle East, Latin American, and Africa. David holds an M.A. in Applied Linguistics/TESOL. He is currently based in Singapore. Nancy Douglas has been in the English language teaching field since 1991. She has worked as an instructor and materials developer in Korea and the United States. She has co-authored several series for National Geographic Learning, including World Link and Reading Explorer, and has edited print and Web-based materials for students as well as professional development courses for teachers.