Practice, not a test. Answer, get instant feedback with the reason, and learn from anything you miss. Nothing here is recorded against you.
Tick each part as you finish it
Mastery check. Ten questions drawn from this unit, and you need nine right, so one slip will not fail you. The pass mark is high because a skill you only half know is a skill you cannot rely on. You can retake it as many times as you like, with a short gap between tries.