However, I must provide an important clarification before developing this article:
This feature transforms the from a passive background resource into an interactive tutor. It solves the three biggest problems students face with older preparation materials: However, I must provide an important clarification before
: A digital version of the course, including potential audio or companion files, is sometimes available for "borrowing" on the Internet Archive : While primarily for the PDF of the coursebook, including potential audio or companion files