Solidball-capturing at the surface and perfectly matching sponge hardness promote extra spins and control at ball contact.
稳固的咬球，完美的配合了海绵的硬度提升了超级旋转及控制力。
2
What the researchers found deep in the lunar interior: a solid iron ball 300 miles across, wrapped in molten iron another 56 miles thick, topped with a 93-mile layer of partially molten material.
It will tell you, say that you have a very small solid, I don't know like a ping pong ball in your flow, it tells you how it is going to start rotating.