Hi!

First of all, thank you for the critique! It's very helpful to get someone else's view on your work, so that you can spot your errors and improve your weaknesses.

Your critique was descriptive and structured, which I appreciated. I tried following your comments while redoing the exercises, please tell me if they still need some work!

Revision exercises: https://drive.google.com/file/d/1eVAaRwKFU8d6tW9lxq_Ym9yGRLn9ajHw/view?usp=sharing

Note: For the contour lines, I did the full-ellipses and half-ellipses on the same page.