Starting with your cylinders around arbitrary minor axes, your work here is by and large well done, although there is of course still room for improvement. You've done a good job of pushing the variation in rates of foreshortening across the set, and your error-checking of the minor axis alignment is quite fastidious - you've caught discrepancies that were quite small that some might otherwise ignore. Doing so is important, as it helps us avoid plateauing when we get into that range of being "close enough". I did notice that earlier on you were prone to drawing your cylinders quite small - this did continue throughout the set, but I did see some trends towards drawing bigger and improving on this front, but keep pushing that further still. And, in doing so, be sure to engage your whole arm when drawing those ellipses, and employ the ghosting method in order to help yourself in doing so. Your ellipses are progressing well, but there is at times still a tendency to be a little stiff and uneven, which often comes with slipping back to drawing from the elbow.

One last thing to keep in mind - and you may already understand this to a point, whether consciously or unconsciously, but I feel it will be to your benefit to point it out anyway - is to consider the relationship between the shift in degree from one end of the cylinder to the other, and the shift in the scale of the ellipse from one end to the other. Both of these 'shifts' help to convey just how much foreshortening is being applied to the given form - and in so doing, it conveys to the viewer how much of the cylinder's length is visible on the page, versus how much exists in the 'unseen' dimension of depth.

The thing is, because they both represent the same thing, this also means that these 'shifts' must operate roughly in tandem. As we get a more dramatic shift in scale, due to the sharper convergence of the side edges, we should also be seeing a more dramatic shift in degree to match.

Continuing onto your cylinders in boxes, by and large you've done a great job here, and I can see clear improvement over 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.

In being fastidious and consistent in the application of your line extensions, and keeping an eye on where they drift apart, you've made visible improvements in your estimation of those proportions, anad you've hit a point where, though there is certainly still plenty of room for growth, you should be able to estimate the proportions well enough regardless of how your boxes are oriented - something that will help you a fair bit into the next lesson.

The only thing I want to call out here is that your linework does seem just a tad rushed - I think you could definitely be investing more time there, similarly to the ellipses in the previous section, to yield greater control and confidence in your marks.

Anyway, I'll go ahead and mark this challenge as complete.