The "Happy English.ru" series for Grade 3 typically includes:
GDZ.ru – Offers organized lists of tasks by page and lesson. gdz po rabochej tetradi-3 po anglijskomu jazyku kaufman
Dzen – Features video explanations and articles walking through specific lessons. Workbook Structure The "Happy English
You can find comprehensive solutions on major educational platforms: gdz po rabochej tetradi-3 po anglijskomu jazyku kaufman