Practice review quizzes are managed automatically by a spaced review system (SRS). From each lesson that you complete, several items are entered into the SRS and will reappear after a certain amount of time as a practice quiz. When you answer a quiz correctly, the longer its interval becomes. (FYI, the final interval is about 6 months!)

※[Update 12/2025] We expect to revamp this tool soon, so stay tuned… 🚧