Starting with the cylinders around arbitrary minor axes, there's one thing that definitely stands out - your linework is, as a whole, kind of sloppy. It's not that you don't have instances that come out really well - for example, this one from this page shows fairly confident side edges, and ellipses that maintain smooth, even shapes, which all contributes to the general solidity of the resulting form.

That said, there are plenty of cases scattered across this set where your lines get wobbly and hesitant, in a way that suggests that you're not as consciously applying all three stages of the ghosting method to each and every mark you draw. Now it's definitely something you improve upon over the set - this earlier page for example shows the tendency for your side edges not to come out straight, and for the ellipses themselves to be quite hesitant, throwing off the consistency of their shape. Your later pages don't suffer from the issue to nearly the same extent, which shows that you are improving - but I'm still seeing instances here and there, even throughout your last page where your marks tell me that the issue is with your approach, not your level of skill.

Long story short, don't treat the ghosting method as an optional thing - it is a process you need to be employing for each and every one of these marks. First you figure out the specific nature of the mark you want to execute, where it needs to start/stop if applicable, what space it needs to occupy, and what its job is meant to be. Then go through the motion of executing the mark through ghosting, helping to identify the way in which you can best approach it. Finally, execute it with a single, purposeful stroke, free from hesitation. Mistakes will happen - your only job is to commit to the choices you've made and push through.

With that out of the way, there's one last thing I want to stress for these cylinders. The rate of foreshortening that is applied to a given form is going to manifest in two distinct, but related ways. There's the shift in scale, which we can see in how the ellipse closer to the viewer is larger overall, and the end farther away is smaller. This is inherently part of what happens when those side edges converge towards the vanishing point.

The other shift is in degree, where the end farther from the viewer is wider, and the end closer to the viewer is narrower. You're more or less aware of this, but the thing to keep in mind is that these two shifts occur in tandem. As the shift in scale becomes more dramatic, make sure that you're matching it with an equally dramatic shift in degree/width. When you don't - in cases like this one from the last page, it can make the cylinder feel off, because one of the "shifts" is telling us there's more foreshortening and therefore more of the cylinder's length exists in the unseen "depth" dimension of space, and the other shift is telling us that there's less foreshortening and that the majority of the cylinder's length is that which is visible on the page.

Of course the viewer won't know exactly what's wrong, but they will be able to pick up on the fact that something looks off.

Continuing onto your cylinders in boxes, I feel as a whole your linework here has definitely improved a fair bit, and you're showing a lot more patience and care as you move through the steps prior to the execution of each mark. You're also applying the analysis very effectively, and improving as a result as you push through the set.

This exercise is really all about helping develop students' understanding of how to construct boxes which feature two opposite faces which are proportionally square, regardless of how the form is oriented in space. We do this not by memorizing every possible configuration, but rather by continuing to develop your subconscious understanding of space through repetition, and through analysis (by way of the line extensions).

Where the box challenge's line extensions helped to develop a stronger sense of how to achieve more consistent convergences in our lines, here we add three more lines for each ellipse: the minor axis, and the two contact point lines. In checking how far off these are from converging towards the box's own vanishing points, we can see how far off we were from having the ellipse represent a circle in 3D space, and in turn how far off we were from having the plane that encloses it from representing a square.

As I can see it, your capacity to estimate those proportions as the boxes are rotated every which way is coming along very well, and should serve you well into the next lesson.

Since the second section of the challenge does largely correct the major issues of the first, I am going to happily mark this challenge as complete. Just remember - don't slack on the use of the ghosting method in the future, whenever you freehand any of your marks.