Speed is not something we take into consideration. That is honestly just a distraction and each box should take as long as it needs to. Students often find themselves preoccupied with how quickly they should be going and tend to get sloppy as a result. Looking through your boxes, you did not seem to get sloppy though and this is proof that mindful practice leads to a consistent increase in speed. Your line quality is looking great throughout the challenge and your boxes are feeling very solid. Your sense of how to get your lines to converge uniformly is also looking great. To be honest I'm having a hard time finding anything to really critique you on. Adding hatching would have been a nice additional practice in lines, but that's ok as your lines are already quite confident. You did a good job varying your orientations of your boxes and rates of convergences but I would have liked to have seen some larger ones, as larger boxes bring their own set of challenges. Just remember to practice large ones in your warm ups so you're not rusty for lessons 6 and 7. Additionally you could have done more with your lineweight to give your boxes more solidity.

For the sake of completeness I will link the infographic uncomfortable made about parallel lines even though you are showing a good grasp of how all of the parallel lines are connected and related to one another, so if you have any questions regarding that just let me know.

Overall you have done a great job with this challenge, as indicated by my sparse critique. I will now be marking this challenge as complete. Congratulations.