Starting with your arrows, nicely done! I'm glad to see a consistent application of perspective both on the positive space (the width of the arrows themselves) and the negative space (the distances between the zigzagging sections). Many students miss the latter, and don't quite show the sense of depth that you're able to capture here, so great work there.

Moving onto your organic forms with contour lines, you're generally moving in the right direction as far as your sausage forms go (keeping them simple) though you do still have a tendency to end up with slight pinching through the midsection, and ends that aren't quite spherical (they tend to stretch a little). Don't forget this part of the instructions.

Secondly, you seem to be using the same degree for your ellipses (for the most part - some of them vary but it seems to be inconsistent rather than the kind of natural, gradual shift from thin to wide or wide to thin that we instead need to be seeing). The degree of the ellipse represents the orientation of that cross-section relative to the viewer, which changes depending on where along the given sausage we're sampling (as shown here). So when you draw a contour line or contour ellipse, think about the orientation of that particular cross-section and how you're going to reflect that in its degree.

Your texture analyses are fantastic. You're showing a really excellent grasp of the fact that we want to focus on shadow shapes rather than lines and outlines. The only one issue is that you largely appear to have missed the point on the big black bar we add at the left side of each density gradient. Its purpose is to give us something to blend seamlessly as we move from left to right. In most of your cases, you have a very visible jump where your texture starts, meaning that you haven't been able actually push your texture to full black. I suspect this is just because you forgot about this part of the exercise, as you're clearly capable of pushing your textures just a little bit further.

Similarly you're doing a great job with your dissections, with a wide variety of textures being experimented with, and an overall effective use of shadow shapes over line. Very well done.

Your form intersections are coming along well. You're doing a good job of capturing the forms together within the same scene in a manner that feels cohesive and consistent. You've also got a good start on the intersections, though keep in mind that as far as this aspect goes, this exercise is only meant to serve as an introduction to the idea of understanding the relationships between our forms in space. Spatial reasoning is one of the core elements of Drawabox as a whole, and while we first touch upon it very lightly here (by just having students try their hands at figuring them out), the real improvement on that front will happen over the course of the next many lessons. So, while you've got a good start, there are a number of mistakes that are entirely expected and completely normal.

Lastly, your organic intersections are doing a great job of demonstrating how these forms interact with one another as three dimensional forms, in how they slump and sag to find a state of equilibrium and stability. You've pushed past the idea that these are just flat shapes pasted on top of one another on a flat page, and are doing well to convince the viewer that they're looking at something three dimensional.

All in all, great work. I'll go ahead and mark this lesson as complete.