Alrighty! Starting with the first section, the cylinders around arbitrary minor axes, you've largely done a pretty good job here. You've been quite consistent and conscientious in analyzing the minor axes of your ellipses afterwards, and the majority of your ellipses are fairly well drawn, with just a small handful being a little more hesitant (which makes them a bit more uneven).

One thing I did notice was that you for the most part tended to keep the foreshortening of your cylinders fairly minimal, opting instead to keep the side edges of the form roughly parallel. With exercises like this, it is best to try and vary the rate of foreshortening, including some that are more shallowly foreshortened, and others that are foreshortened more dramatically.

That said, there is something related to this that I noticed, which is worth calling out. Foreshortening in our cylinders is represented by two different kinds of shifts from one end fo the form to the other. One is the overall scale, with the farther end being smaller than the closer end (this is a pretty normal aspect of perspective people at this stage are familiar with). Then there's the shift in degree from one end to the other, where the farther end is generally wider than the closer end.

The thing is, both these 'shifts' must work together. We either get a more significant shift of both scale and degree, or no shift at all. So if we look at cylinders like 115, where there's a more notable shift in degree, but no shift in scale, this becomes contradictory. There, the shift in degree tells us there's lots of distance between the two ends, whereas the shift in scale says that there's fairly little space in between those ends. Keeping these things consistent is important, so keep that in mind.

Looking at your cylinders in boxes, here I think you've done a solid job across the board. You're still pretty mindful of applying the ghosting method to your lines, and you're doing a great job of checking the additional line extensions consistently. The key to this exercise is that it focuses on developing our ability to construct boxes that feature two opposite faces that are proportionally square. The way this works is by taking the concept of the line extensions from the box challenge, which gradually help us develop our ability to intuitively approximate the convergences of our lines (by attempting, analyzing, and then attempting again over and over) and adding the three lines the ellipses introduce. The minor axis and contact point lines will only converge towards the box's own vanishing points when the ellipse itself represents a circle that sits within one of the box's faces - and so by checking these extensions and making small adjustments to bring them more in line, we gradually build our ability to intuitively maintain those proportions.

To that end, I think you've made great improvement, and while these lines aren't always consistently converging to the same vanishing points, I think you've gotten better at it, and the results are coming out much better to the naked eye. This should come in quite handy throughout the next lesson. Aside from that, you're still maintaining excellent line quality and are making solid use of the ghosting method throughout.

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