Hey Wenhan! Good job on these. You were successful at turning them in space, which is definitely the hardest part of that lesson. A few small things I'd add, the first being taking good photos of your art. This is more of a nitpick than anything, but it's more of a good habit to get into. These aren't bad photos, but they don't look "cool". When you present a piece of art, even a study, everything comes across in the final image including the quality of the photo. The next thing is that I'd watch the width of these. It looks like they get a bit wide towards the neck a lot of the time. Something that might help is to simplify your process. To me right now it looks like you're thinking from piece to piece, rather than a big shape. If you were to start with a singular large oval, then carve from there it might help unify them a bit more. The last thing is to clean your lines up a bit. I'm not sure if it's the paper, or the pencil. But they seem a bit rough, and stiff. I think what will solve this is drawing large to small, which is essentially just starting with a big shape then carving from there. @Sinix has a great video on his YouTube channel "Painting Like a Sculptor" that goes into the thinking behind that. Hope this helps!