Starting with the cylinders around arbitrary minor axes, your work here is generally pretty decent. I am somewhat concerned about your linework - it's visibly hesitant, resulting in subtle but noticeable wavering, and I'm not seeing any signs that you're applying the ghosting method to these. Note that we do require students use the ghosting method for any and every mark that is freehanded throughout this course. It's pretty easy to get a little too comfortable and to stop thinking about how actively you're applying all three stages of the process to each and every mark - and so if we aren't attentive and intentional with it, we shift from properly investing our time to the planning and preparation phases, then executing with confidence, to reducing how much time we're willing to invest in those planning/preparation phases, and compensating by spending more time on the execution... which brings us right around to the opposite of what the ghosting method is all about.

As a whole, this course really focuses on being hyper-intentional with every choice we make throughout the process. It's tedious, it's boring, it's exhausting, but in doing so we rewire our brain and what it considers "normal" so that when we're drawing outside of the course, even if we're not consciously trying to apply these methodologies, we still fall into those patterns of behaviour - even if it means thinking for a split second about the nature of the mark we wish to draw before we draw it.

Aside from that, you are generally doing a good job of checking the alignment of your ellipses, and I'm pleased to see that you've included a wide variety of rates of foreshortening. The only other thing to keep an eye on aside from how you're executing your marks, is to draw through each of your ellipses two full times. It seems you intend to do so, but again - because you're not being as attentive to what you're actually doing, you frequently fall short, drawing only 1.5 turns of the ellipse instead of a full 2.

Unfortunately while the first section of the challenge was overall decently done despite the issues I called out, you don't seem to have taken as much care as you should have in following the instructions for the cylinders in boxes. 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.

Looking at your work, you do not seem to have actually applied the line extension instructions correctly - you only extended your boxes' lines and identified the minor axis for each ellipse, and did not apply the 2 contact point lines for each ellipse, so you did not gain the benefits the exercise was designed to impart. While it's a lot of work, it does mean that you're going to have to redo that section.

When doing so, be sure to aim to have each ellipse touch all four edges of the plane enclosing it (cases like 227, 231, and 233, as well as some others had some issues in this regard, although this is something you did correctly for the majority of cases), and also ensure that you are extending your lines in the correct direction (again, you largely did this correctly, but there were a handful of cases towards the first half like 155, 156, 157, 172, 193) where your lines were extended in the wrong direction. This approach from the box challenge can help you consistently extend your lines in the right direction based on the Y you start with).