Starting with your cylinders around arbitrary minor axes, I can see that you've made a solid effort to vary the rates of foreshortening across the set - although I do see cases where you appear to be forcing your lengthwise vanishing point to infinity, as we see in cases like 77 and 79 on this page and 59 on this page (there are a few others, especially towards the beginning of the set). It's not a continuous pattern, but it is still worth calling out as this is something that was specifically addressed as incorrect and to be avoided in these reminders, so be sure to keep that in mind going forwards.

When it comes to your linework, generally speaking it's coming along decently, although I did notice some spots (not a ton, but a few) where you allowed yourself to give into the temptation of correcting mistakes (as we see on the side edge of 12 as well as on 83 and 87, 88, and 90 on this page, among a few other cases. Do keep in mind that correcting a mistake will simply address the symptom, while tricking your brain into thinking that its cause was addressed. This makes it no more likely that you'll take the additional time required to think through your process and apply each step mindfully and patiently so as to avoid that cause in the future. Allow your mistakes to stand for themselves, and absolutely do not allow yourself to make marks reflexively, without thinking. Every aspect of what we do throughout this course needs to be as intentional as possible, as the goal is to develop our auto-pilot to be more reliable, so that outside of this course we can depend on it to free our conscious mind's cognitive resources for more creative choices like composition, design, etc.

Of course we only get there by being as intentional and mindful as possible here, and bearing all of the tedium that comes with it. While your linework is generally okay, I do get the impression that a bit more time for the planning/preparation phases of the ghosting method, both for your straight lines and the ellipses, would benefit you in this regard.

Lastly there were a few spots early on where you got the degree shift between the closer/farther ends of your cylinders inverted, but this wasn't frequent enough to be a concern.

Continuing onto your cylinders in boxes, though the tools you used for some of your line extensions (like the neon yellow highlighter) are less than ideal, and you started out with a number of cases with your lines extended in the wrong direction (as we see on this page), by and large you're applying the steps correctly. 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.

My only concern here is that you aren't extending your minor axis lines as far back as the others (contrary to the instructions), and as a result, make it considerably more difficult to assess whether it convergences consistently with the boxes' edges or not. Instead you appear to have confused it with the first part of the challenge, where we only need to identify that alignment locally, without needing to perform a broader analysis as we do here. You also appear to have included extensions for the cylinders' side edges, which isn't a problem, but it does arguably contribute to more visual clutter which could make it harder to make those comparisons as well. Personally I don't mind the side edges being extended, but it is very important that you ensure the minor axes are extended all the way back.

I'll go ahead and mark this challenge as complete - but I do recommend that you pick up a pack of coloured ballpoint pens if at all possible, rather than using half dried markers and neon highlighters for your line extensions when applying this exercise in the future. Sure, it's workable, but it's really far from ideal and it definitely makes things more difficult when providing feedback.