Jumping right in with your cylinders around arbitrary minor axes, I noticed that while you do have a fair number of cylinders to whom foreshortening has been applied, there is also a large quantity of cylinders where you've kept the side edges of your cylinders parallel on the page, specifically forcing their lengthwise vanishing points to infinity. This is something we actually address quite specifically in the lesson notes here in this reminder section (specifically the second point presented there). While it would be much worse if this was an issue present throughout the entirety of the set, it is a bit worrying that despite being very specifically mentioned, it still came up as often as it did (I didn't do a proper count, but I wouldn't be surprised if it constituted half of the set).

In addition to this, I did notice a number of cases - 108, 110, 126, 127, 130, etc. to name a few - where you did not appear to apply any shift in the degree of the ellipses from one end to the other, and focused instead only on the shift in scale that results in the side edges converging. In fact, it seemed more that you would focus on one of these shifts at a time in most cases, instead of applying both consistently with each cylinder. The thing is, these two shifts (again, the shift in the overall scale of the ellipse resulting in converging side edges, and the shift in the degree from one ellipse to the other) serve as the visual manifestations of foreshortening, and help convey to the viewer just how much of this cylinder exists in the unseen dimension of depth.

As they both represent the same thing, they work in tandem - the more we shift the scale and the more those side edges converge, the more that degree is going to shift wider on the far end to match. It doesn't have to be any specific amount, just be sure to avoid situations where one shift is extreme and the other is minimal.

As to the checking of your minor axis alignments, you handled that fairly well - although I am concerned about how you're handling your foreshortening so I will be assigning revisions for that.

Moving onto your cylinders in boxes, by and large you've handled these better. 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.

There are two main points I do want you to keep in mind going forward with this exercise however - firstly, don't get too comfortable with identifying your minor axes, as it's very easy if we don't pay enough attention to assume our alignments are more correct than they are. For example, here the actual minor axes are a fair bit off from what you marked out. You're going to find yourself being prone to making this kind of mistake more often with boxes that are especially stretched, so that's a good cue to pay more attention (although in general it's a good idea to always take enough time to avoid these problems altogether).

Secondly - this one's related to the first - note that for this exercise, we want you extending the minor axis lines all the way back with the others, as the intent is to compare how they are converging compared to the box's edges. It seems here you may have conflated it with how we identify the minor axes in the previous section of the challenge, rather than following the instructions to the letter.

All in all though, your work on this part of the challenge is solid. I'll only be assigning revisions for the first part, which you'll find assigned below, although when you do submit them please use an image host that does not require me to click through each page individually, and ideally allows me to scroll through them at a good size. Imgur is what we generally recommend, as it greatly improves the efficiency with which we're able to provide feedback.