How about the twelfth floor on the top floor?

It's good to buy 12 floor, neither high nor low. This is the brightest floor. Tall trees can't reach this height, so the light is not easily blocked. Dust particles in the air are mainly on the floors below 12. 12 floor has good ventilation and lighting. The eighth floor to 1 1 building is the dust layer in environmental science, and the dust and harmful substances in the air always stay at this height.