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. Helen Huntley is currently the Vietnam Director of a cooperative undergraduate 2+2 program between California State University, San Bernardino, and the National Economics University, Hanoi, serving as liaison between the two universities and directing the English language program. She was Director of the Intensive English Program at West Virginia University in the United States from 1996-2006, followed by a year as a Senior Fulbright Scholar in Mexico, and three years as a Senior English Language Fellow in Vietnam. She is a published author and consultant for National Geographic Learning, and has presented at numerous international conferences on a wide variety of educational topics. In addition, she has assumed leadership positions in professional educational organizations in the United States and has consulted on a variety of educational projects. Nancy Douglas is a teacher, materials writer, and editor who has been in ELT for over twenty years. She has extensive experience working with students from around the world and has co-authored several courses, including the best-selling series World Link and Reading Explorer. She has also edited print and Web-based materials for English language learners as well as professional development courses for teachers. David Bohlke has over 30 years of experience as a teacher, teacher trainer, program director, editor, and materials writer. He has lived and worked in Japan, Korea, Singapore, Australia, Saudi Arabia, and Morocco, and has conducted multiple teacher-training workshops in Asia, the Middle East, Latin America, Africa, and the Pacific. As an editor he has worked on some of the world�s best-selling ELT courses for teens and adults. For National Geographic Learning he has authored the series Time Zones, Keynote, and Reading Explorer. David holds an M.A. in Applied Linguistics/TESOL.