the inside lower horizontal surface (as of a room, hallway, tent, or other structure)

the inside lower horizontal surface (as of a room, hallway, tent, or other structure)

the inside lower horizontal surface (as of a room, hallway, tent, or other structure)

the inside lower horizontal surface (as of a room, hallway, tent, or other structure)

the inside lower horizontal surface (as of a room, hallway, tent, or other structure)

the inside lower horizontal surface (as of a room, hallway, tent, or other structure)

the inside lower horizontal surface (as of a room, hallway, tent, or other structure)

the maximum altitude at which an airplane can maintain horizontal flight

the maximum altitude at which an airplane can maintain horizontal flight

the maximum altitude at which an airplane can maintain horizontal flight