hairlike structures that extend from the surface of the cell, where they assist in movement. they are longer and are far less numerous on the cells where they occur.
Fill a U.S. Customs form to track the package abroad or ask your correspondent the parcel's bar code. Note the number that starts with CP on top of the form. Go to usps.com/shipping/trackandconfirm.htm?from=home&page=0035trackandconfirm. Enter the form number. Click Go..
Source Identifier. The next two digits of the USPS tracking number are the source identifier. This two-digit code identifies the shipper. Each shipper has its own source identifier, used in conjunction with a longer mailer ID number, also found on the USPS tracking number label.