The lines are clean with a few instances of redrawing them here and there. Would have rather the correction lines be in red to make it more readable, but it was not that much of a problem.

Boxes are wonderful to do as warmups, so when you practice your boxes here and there, keep in mind these middles lines need to converge. I can see you've probably noticed these in most of your drawings, so this is just something to keep in mind for future boxes and perspective.

https://imgur.com/chFfAWo

Overall, great job. You've accomplished the purpose of this challenge and feel free to move on to lesson 2. I will mark this as complete.

Happy studying.