If the glass were kept hot enough, it would flow over the molten tin until the top surface was also flat, horizontal and perfectly parallel to the bottomsurface.
如果玻璃保持足够的温度，它就会在熔化的锡中流动，直到顶部表面也变得平整、水平，与底部表面完全平行。
2
A package with pins distributed over much or all of the bottomsurface of the package.
一种封装，插脚分布在封装底部的大部分或全部表面。
3
The concrete foundation bottomsurface should be smooth solid, not into the pot bottom.