Answers. Best Answer: FL means Flight Level. It's used above 18.000ft (in the US, in other countries other altitudes are used as the boundary) to indicate the altitude in hundreds of feet. So FL230 is 23.000ft standard altitude.est Answer: FL means Flight Level. It's used above 18.000ft (in the US, in other countries other altitudes are used as the boundary) to indicate the altitude in hundreds of feet.
The nostrils, which form the external entrance of the nose, lead into the two nasal cavities, which are separated from each other by the nasal septum, a partition formed of cartilage and bone. Three bony ridges project from the outer wall of each nasal cavity and partially divide the cavity into three air passages.
Anatomically, a nose is a protuberance in vertebrates that houses the nostrils, or nares, which admit and expel air for respiration in conjunction with the mouth. Behind the nose are the olfactory mucosa and the sinuses. Behind the nasal cavity, air next passes through the pharynx, shared with the digestive system, and then into the rest of the respiratory system. In humans, the nose is located centrally on the face and serves as an alternative respiratory passage especially during suckling for infants. On most other mammals, it is located on the upper tip of the snout.