Hi, I've been seing your submission for the lesson 2 and this are my comments about it:

The two pages on arrows I think are pretty well done, I've noticed some minor mistakes in the hatched but nothing too serious.

the exercieses about contour lines are good although some ellipses got out of the form, but the flow is good.

The firt exercise about texture is a bit weak but the next two exercises about dissections showed a great deal of work an the improvement is really noticeable.

Interseccion pages are good but the lines need to be a bit mor confident specially the spheres and cylinders.

The last exercise is good, the shadows are clear and help to understand the form underneath, the flow of the lines could be a bit better.

I hope this is helpful and I really think the concepts are clear and well applied so I think you can move to the next secction.