Instructive and easy to understand.
Only two issues, both with the exam.
1: on my PC , the exam question that had you drag pictures to the correct line was new and novel. I must be using a different browser or settings. It was a glitchy confused mess. When I grabbed the picture, my screen became white and the choices flickered in and out of existence when I waved the mouse pointer on the screen.
2: the only question I got wrong. Was what constitutes the escapement. I did not choose the balance complete, due to the fact that the balance complete, in my mind, includes the balance bridge. That would indicate that the train bridge was part of the train of wheels. Just made me scratch my head a bit.