Name a common physical characteristic of UXO.

A distinct cylindrical shape or tailfins in aerial bombs is a common physical characteristic of unexploded ordnance (UXO), particularly those that come from aerial bombs. This shape and the inclusion of tailfins are designed for aerodynamic stability, allowing the bomb to glide and fall accurately during its deployment. Identifying these features can be crucial for UXO technicians and bomb disposal experts when assessing a potential hazard on the ground.

The other characteristics listed may not be consistently applicable to all types of UXO. While some ordnance may have a shiny metallic surface, this is not a reliable identifier due to weathering, corrosion, or varying materials used in their construction. Bright orange color is typically associated with training ordnance or markers, not with live UXO. Finally, while warning labels might indicate danger, they are not a physical characteristic of the ordnance itself, as some items may lack such labels altogether.