CS Assignment I Don't Understand
I don't think that there any any labs this year that I completely don't understand, but if I had to name one, I'd say it was lab 6. This lab dealt with structures. While I do know how to use structures pretty effectively right now, I still find scheme's implementation of them somewhat confusing, especially in terms of changing structures rather than just making new ones.
Link
Lab 6: A link to the pdf of the Lab 6 source code.