While I do think you started out quite visibly weak (your linework was kind of hesitant and uncertain), I think you definitely improved a great deal on this front throughout the first section of this challenge. As you pushed through, your ellipses became more confident and consistent, and as a result your cylinders started becoming more and more solid. You also held to being fastidious in checking your ellipses' minor axes, taking care to identify even small deviations, and as a result those alignments kept getting better. Towards the end you did still have some instances where you only drew around some ellipses once (instead of going around two full times as discussed back in Lesson 1), and some of them were still sometimes a little stiff (be sure to use your whole arm, from the shoulder, and employ the ghosting method), but all in all this is considerable growth.

Looking at your work here, there is one thing that I do want to point out and explain. Foreshortening itself manifests in our forms in two ways. There's the shift in scale where the ellipse closer to the viewer is bigger and the ellipse farther away is smaller. Then there's the shift in degree, where the end closer to the viewer is narrower and the end farther away is wider.

All of these shifts tell us just how much foreshortening is being applied to the given form - and therefore just how much that form is tilting towards or away from the viewer. No foreshortening at all tells us it's moving straight across our field of view, and lots of foreshortening (along with ends that come closer together and even overlap) tells us that the form is coming right at us.

The thing you're missing - most notably in examples like 131 on the bottom left of this page - is that these two 'shifts' occur in tandem. They do not occur independently (with the scale shift being more dramatic but the degree shift being more minimal) - they both have to happen at roughly the same rate. So in 131, the far end should definitely be much wider to match just how much smaller it is.

Continuing onto your cylinders in boxes, these are definitely moving in the right direction, though there is something I want you to pay closer attention to.

This exercise is really focused on constructing boxes - specifically boxes that feature two opposite faces which are proportionally square. In the box challenge, we employed the line extensions to help students build up their instincts in regards to drawing lines that converge more consistently with one another. Here, we extend that further with the ellipses and their own lines (the minor axis and the two contact point lines) to develop students' instincts when constructing these specific kinds of boxes.

By testing whether the ellipses' lines converge towards the box's vanishing points, we can see how far off we are from having the ellipses represent cirlces in 3D space, and in turn, how far off we are from the plane enclosing said ellipses from representing squares.

Now, there's one thing I feel you may not be paying quite as much attention to - that's the minor axis. As shown here, some of those minor axes are way off the mark, and you haven't identified them correctly. It's very easy in some cases to confuse the minor axis with one of the contact point lines - but remember that the minor axis needs to be running down the spine of the cylinder. This page was particularly bad (with more squashed cylinders), and the others were definitely better, but I did feel that overall you could have stood to be more careful in identifying those minor axes. Furthermore, be sure to extend them all as far as the other lines, as the intent here is to test them against the box's vanishing points.

So! Keep those points in mind - I'll go ahead and mark this challenge as complete.