Great job. You definitely improved by the time you got to the boxes.

Lines became more straighter, and the whole artwork got also way clearer!

I think your ellipses will need some extra attention in the future - I think by now, you can get them tighter the next time you need an ellipse. Remember to ghost them out and imagine the ellipse you want. You can draw the ellipses just the way you want, so leave nothing to chance!

The rotation boxes exercise is great, and the shading you did on the plotted perspective, I love it!