a dance floor的用法和样例：
- How big a dance floor can the ballroom hold?
- Daylight must be visible between partners on a dance floor.
- A dance floor is a level area specially prepared for dancing.
- You can't see their smile or bring them food or tousle their hair or move them around a dance floor.
- It has a dance floor with a length of 18 meters and a width of 15 meters. It is equipped with two 10ft by 6 ft video screens.