What Is a Social Security Number (SSN)? A SSN is a nine-digit identifying number is in the format xxx-xx-xxxx. Any individual who is a U.S. Citizen, a permanent resident, or a temporary alien resident who is authorized to work in the United States, must have a SSN.
The most common cause of a flat tire is puncturing of the tire by a sharp object, such as a nail, letting air escape. Depending on the size of the puncture, the tire may deflate slowly or rapidly.
Flat tire. See also: Run-flat tire. A flat tire on an automobile. A flat tire (British English: flat tyre) is a deflated pneumatic tire, which can cause the rim of the wheel to ride on the tire tread or the ground potentially resulting in loss of control of the vehicle or irreparable damage to the tire.