The Daily Train page is where you can practice on the quiz questions.

When you get a quiz question correct, it levels up, and you do not see it again until later. Say you achieve level 7 with a quiz question when you get it right today. That quiz question will not appear in Daily Training for another 7 days.

But if you get a quiz question wrong, you go down one level, and you have to try to get it right again before it disappears from Daily Training.