A cell that carries out the final response or function of a particular process. The main effector cells of the immune system, for example, are activated lymphocytes and phagocytesâthe cells involved in destroying pathogens and removing them from the body.
Best Answer: Yes you can track it online here: https://tools.usps.com/go/TrackConfirmAc... The tracking number should look like this: CP 000 000 000 US. You can find it on the receipt, and the customs form you filled out.
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.