If they have to review something that they should have learned a couple of weeks ago, or maybe a couple of years ago, they don't have to be embarrassed and ask their cousin.
繰り返し再生したりできます 何週間前とか 何年前とかに 学んでいたはずのことを 復習しなければならない時も 恐縮しながら頼む必要はありません