What¿s it like to build your own airplane? Why are strong bones important? How did the tradition of a wedding cake begin?The Password series uses readings about real people, places, and events to help students develop reading skills and increase their active vocabulary. Each book¿s six theme-based units ¿ including such universal topics as work, travel, and celebration ¿ feature appealing passages, carefully chosen vocabulary, and a variety of exercises to engage and motivate readers.Units are followed by a four-part Wrap-Up section, which uses review and expansion exercises, puzzles, and dictionary skillbuilders to consolidate and enrich students¿ understanding of new words.Other features in the Password series include: Target word choices based on analyses of authentic language data in various corpora, including the Longman Corpus network. An emphasis on systematic vocabulary acquisition, including carefully controlled sentence structure and recycling of vocabulary. Activities that highlight collocations and word grammar. Periodic vocabulary self-tests to help students assess their own progress. A Teacher¿s Manual with an answer key for all student exercises, six unit tests with answers, and a Quick Oral Review for rapid vocabulary drills.