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.
To be blunt â bald tires arenât safe â for a number of reasons. Although you may not have had a flat or a blowout at high speed, bald tires can lead to a loss of control, hydroplaning, and understeering.