封顶的英文：
closedtop

Complete(a building)by adding the highest stone,etc
(用石块等)给(建筑物)封顶.

There will be no ceiling or floor in giving bonuses to the employees
对员工的奖金实行上不封顶，下不保底

The building is roofed entirely with translucent corrugated plastic.
这座建筑完全用半透明瓦楞塑料封顶。