Since you are looking for a write-up on the or "Keys" for this specific book, Overview of the Course & Solutions
: Natalia Ivanovna Kolesnikova and Galina Mikhailovna Kotova. gdz po frantsuzskomu potushanskaia nachalnyi kurs
The course focuses on a non-traditional introduction of phonetics, grammar, and vocabulary specifically designed to build quickly. Because the exercises are rigorous, students often use the "Ключи" (Keys) manual for self-checking. Since you are looking for a write-up on