When they have reached the size they want, they use an implement such as a rock or shell to smooth the surface of the pot.
参考译文：做出想要的尺寸时，他们用一个工具，比如一块石头或贝壳，将罐子的表面弄平滑。
2
Main products are: the ice thermos bottle, plastics, vacuum flask, stainless steel heat kettle, coffee pot, pneumatic iron shell, etc.
主要产品有：保冰保温瓶，塑料保温瓶，不锈钢保温壶，铁壳咖啡壶，气压瓶等。
3
The paper makes a theoretical analysis of blushing of the potshell from the thermal equilibrium point of view and puts forward some countermeasures for them in terms of process management.