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.
Repair of larger tread punctures and of punctures to the tire's shoulder and sidewall areas are not recommended.. While almost any sharp object left on the road can cause a puncture, most are caused by small nails and screws (typically less than 1/4 in diameter).