Many of the questions are hard to understand and repeat often with different answers that contradict the first answer given. Sometimes it even seems like the answers change completely when you try to go back a page. The previous question button rarely works, as it just continues the test sometimes and then when you try to go to the question you were just on, it tells you the answer you gave was wrong.
Tdlr: the questions need work, answers are sometimes contradictory, and the buttons don’t work that well.
Could be a really useful practice if it had better written questions.