These are not bad at all, for what is, I imagine, some of your first gesture tryouts? I'd recommend doing about 20-30 per day for a week and you'll see huge improvement. Also, what I did in the first week, was watch/listen at least once per day (as I was drawing) the "How to gesture" (lesson one from the course). If you want to explore excercies just for the lines, I'd suggest you check out "DrawABox" where the first lessons are focused on line quality and how to get longer, sweeping lines. I'd love to see more of your gestures as you progress, keep it up!