These look very nice to me. You're hitting a lot of the main points that people often struggle with. Everything is broken down and constructed into its primary masses well. You're line quality is very clean. You're doing a good job of capturing the separation from the ground plane with the drop shadows. I see a good understanding of how the gesture of the legs move, something that people often struggle with on this lesson. And on the drawings that you textured, it's generally applied well. That said, I do have a few minor pointers for you:

1. Don't forget to draw through your forms. You did pretty well with this on the first few pages, but in the later pages (such as the ant and the scorpion) it seems you neglected to do this.

2. Work on your line weight and separating which forms pass in front of others. For the most part everything here is the same line weight. Thickening things up on the forms that pass in front will help separate them in 3D space and give the drawing more depth.

3. When you put a form down, commit to it. On some of the flies for example, I can see lighter forms for the abdomen portion that don't extend all the way out to the edge of the drawing, as if you put it down then decided it needed to be bigger so made another pass at it. This undermines the solidity of the drawing. Once you put a form down, it's part of the drawing. You can build on top of it or carve into it, but you need to honor that foundation you put down on the paper.

Overall though, this is good and I think you're ready to move on to Lesson 5.

To add to what mark said, don't forget to draw the intersections, both between sausages, like you can see here, and to the body parts themselves. Head and abdomen etc.