Solutions are often found in separate "Teacher's Books" or specific GDZ websites like Gitem.me . 2. Happy English (Classic/90s Edition)
This is the most common version currently used in Russian schools. It is published by and authored by K. I. Kaufman and M. Y. Kaufman . Target Levels: Available for grades 2 through 11. gotovye domashnie zadanija k uchebniku happy english
Focused on authentic British English with a collaborative Russian-British approach. Solutions are often found in separate "Teacher's Books"