Jack's sitting on the floor watching TV.
We painted the wooden floor with a white stain.
In British English, the ground floor of a building is the floor which is level with the ground. The floor on the next level is called the first floor. In American English, the first floor is the floor which is level with the ground and the next floor up is the second floor.
英国英语中，ground floor 指“底层;一层”，first floor 指“底层上面的一层，即二层”。美国英语中，first floor 指“底层;一层”，second floor 指“底层上面的一层，即二层”。
He was floored by the announcement. [be VERB-ed]
He seemed floored by a string of scandals. [VERB-ed]