Slide.
both
I think both
cylinder
The shape that can slide and roll, stack and roll, and has no vertices is a cylinder. Cylinders have curved surfaces that allow them to roll smoothly, and they can stack on top of each other without any sharp edges. Their continuous surface and circular bases provide stability when stacked.
Because the sides are like a circle.
no
Yes
cylinders: slide on the small sides, roll on the round one
You slide,roll,and tumble
a ball
both
Yes
yes. it can slide if on a slippery surface facing downwards
A cylinder
I think both
No
cylinder