Welcome to English. In this introduction, we want to tell you something about the books you are going to be using. NEW ENGLISH 900® is a six-level course for adult students of English as a second language. It contains material from beginning to advanced levels of study. The series consists of six student textbooks, six workbooks, six teacher's books, and reel-to-reel or cassette recordings. This series is a revision of the original ENGLISH 900® which takes its name from the 900 Base Sentences presented in the six textbooks. These sentences cover the basic structures and basic vocabulary of the English language. The Base Sentences of NEW ENGLISH 900® always appear in a complete and authentic context. They are presented in dialogue form as spoken by a cast of fully-drawn characters who use the English language in a natural way to communicate their thoughts, ideas, and feelings. There are 150 Base Sentences in each book, and they are numbered consecutively from Base Sentence 1, Book