Jumping right in with your cylinders around arbitrary minor axes, your work here is coming along very well. I can see that you've put in considerable effort to vary the orientations and rates of foreshortening, and while I caught a couple cases where the side edges were very close to running parallel to one another on the page, there was just enough convergence to make it clear that your intent was not to force the vanishing point to infinity incorrectly. You've also been quite fastidious in checking the alignment of your ellipses, and while it can be tempting to ignore the very small discrepancies, you did not - which is good, because it'll help you avoid plateauing early in what this exercise has to offer you.

I have just one suggestion- take a little more care to ensure that you're drawing through each ellipse two full times. It's easy to lose track and end up falling a little short, which speaks to being less conscious of the choices you're making as you're drawing, so just remember to always strive to be in control. This is a common (albeit minor) issue at this point, so just something to be aware of.

Continuing onto your cylinders in boxes, your work is similarly well done. 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 taking care to apply your line extensions correctly, you've armed yourself with ample information to help you adjust from page to page, steadily honing and improving those instincts. While there is certainly plenty more room for growth, you have improved in this regard, and enough to serve you well into the next lesson.

So! I'll go ahead and mark this challenge as complete. Keep up the great work.