Looking over your work, there's a lot you're doing very well, but insofar as you holding to the points I've raised in my critique of your Lesson 4 work, and holding to the general principles of markmaking from Lesson 1, you have some pretty significant issues in how you're actually approaching these exercises. Fortunately, as your underlying understanding is fairly solid, this is a matter of conscious decisions you're making as you draw, to draw in a particular fashion, and so they should be easily corrected by simply calling out the issues.

In terms of the principles of markmaking from Lesson 1, it comes down to your tendency to draw a lot of separate marks (often straight lines), as though you're actively sketching. This is quite visible when you're building up your additional masses, as shown here. While it is perfectly normal to create these masses' silhouettes by drawing separate marks, it is important that the resulting form's silhouette be completely self-enclosed, without any little gaps to undermine its illusion of solidity.

It is fair to mention that some of this is inevitably the result of the scanner app you're using - it is significantly boosting the contrast of the image, blasting out some of your lighter linework. However you do capture your drawings - whether it's by using your phone's camera, a proper scanner, or a scanner app on your phone, it is very important that the images you're sending in are accurate representations of the drawings themselves. Simply using your phone's camera with decent lighting (natural daylight coming in through the window is usually pretty good for this, avoid lamp light). Scanners will generally have settings that just capture the raw image, but "drawing" related presets tend to try to artificially adjust the result to make the paper itself as white as possible.

Now, while some of the gaps in your linework may be the result of the scanner settings, I can see it to overall be more the result of how you're drawing your marks, and the fact that you're not adhering to the concepts from Lesson 1. Remember that the ghosting method should be employed for each and every mark, forcing you to think and plan before each stroke. Furthermore, you should not be artificially trying to make your earlier constructional stages lighter or fainter. Each mark should be drawn with the same overall confidence, allowing it to play an equal role in the final construction.

Continuing onto the points I mentioned in Lesson 4, there I had stressed the importance of every new addition being a complete, self-enclosed silhouette, drawn with your focus on how it is meant to exist in 3D space, and how it's meant to relate to the forms that are already present. And, as an extension of that, that we should be actively avoiding situations where we're just putting down one-off marks that attempt to enclose spaces against other forms, but without defining a complete form themselves, or without providing us with enough information to understand how this new addition is meant to exist in relation to the other parts of the existing structure in 3D space.

Unfortunately, you do have plenty of cases throughout your constructions that you're adding partial shapes or bridging from one form to another using a one-off stroke. I've identified some such situations on this bird, as well as a more detailed analysis of those kinds of issues in this bear.

While there are certainly cases where this is an intentional choice in terms of how you're deciding to tackle the construction (that is to say, while you may not be actively choosing to deviate from the instructions, you're not reflecting on the manner in which you're deciding to execute these marks and draw these forms in order to ensure that you're adhering to the concepts from the lesson, the course, and the past feedback you've received), there are also other circumstances where these partial shapes are the result of either applying line weight incorrectly, or where you're applying fur incorrectly.

I've marked out on the bear how you're adding fur in a way that extends the silhouette out, rather than simply adding tufts such that they stick right to the existing structure, on the bottom left of the bear drawing. When it comes to line weight however, it comes from the tendency to try and have line weight jump from one form's silhouette to another's, creating a "bridge" across them. As a rule, avoid this. Line weight should be added to the silhouette of one form at a time, and should itself generally be focused on clarifying how different forms overlap one another. We limit its use to the localized areas where those overlaps occur, as shown here.

Continuing on, there are some places where you do have your additional masses drawn as complete, self-enclosed forms - like on this rhino's back - although the specific way in which those forms are designed does not quite establish those masses as wrapping around the existing structure. One thing that helps with the shape here is to think about how the mass would behave when existing first in the void of empty space, on its own. It all comes down to the silhouette of the mass - here, with nothing else to touch it, our mass would exist like a soft ball of meat or clay, made up only of outward curves. A simple circle for a silhouette.

Then, as it presses against an existing structure, the silhouette starts to get more complex. It forms inward curves wherever it makes contact, responding directly to the forms that are present. The silhouette is never random, of course - always changing in response to clear, defined structure. You can see this demonstrated in this diagram.

Here you can see this manner of thinking in action. Note the arrows marking out each specific, intentional inward curve, each one occurring in response to contact with another mass or structure.

For now, I'm going to leave the critique there. You have a number of points to address which I've called out. Once you've done so, we'll be in a better position to address any further issues that may remain in your approach. You'll find your revisions assigned below.