The book is designed so that the units may be used in any order, although the more difficult units naturally appear near the end of the book, in the Work and Study section. the units at the end of the book are more difficult then the units at the beginning of the book. However, you do not need to do the units in order - Kitob shunday yaratilganki, birliklar istalgan tartibda ishlatilishi mumkin, garchi qiyinroq birliklar tabiiy ravishda kitob oxirida, Ish va o'qish bo'limida paydo bo'ladi. Kitob oxiridagi birliklar kitob boshidagi birliklarga qaraganda qiyinroq. Biroq, siz birliklarni tartibda bajarishingiz shart emas.