STAGE 4 INTERMEDIATE. 1700 HeadwordsAs previous level plus - Simple passive forms(except modal perfects) - Present and past continuous passive verb forms - Present simple for future reference - Present perfect continuous - past perfect - Have something done - Make/let+infinitive - Used to - was/ were going to - Had better for advice or desirability - May/might for possibility - Must for deduced facts - Should/ought to for advice, duty and desirability-Would for hypothetical situations - Question tags: positive tag following positive statementsFor thousands of years people have used codes and ciphers to keep secrets from people who will do anything to learn them. How did sectret messages cause a queen to lose her head? How have lost languages finally been understood? How did one little- known language help a country win a war? Read this book and find out.Penguin Active Reading provides reading and language learning at five levels, through full colour, beautifully illustrated Readers. As well as enjoyable stories and texts, each book provides a range of integrated activities designed to develop reading skills and consolidate vocabulary, and offers personalised project work. Each book is supported by an interactive CD-ROM which contains additional activities and the complete audio recording.