OPOSSUMS ARE MARSUPIALS. If you open just about any field guide to North American mammals, the opossum will probably be the very first of the 380 or so mammal species described. That's because opossums are our only marsupial, and marsupials are considered very ancient forms of mammals.
operator - an agent that operates some apparatus or machine; the operator of the switchboard. manipulator. causal agency, causal agent, cause - any entity that produces an effect or is responsible for events or results. company operator - an operator who works for a company. driver - the operator of a motor vehicle.
A private branch exchange (PBX) operator is a person who operates a telephone switchboard. Switchboards are used by large businesses, such as hotels, to handle calls internally as well as receive incoming calls.t an organization that uses a PBX, the PBX operator is the first person callers hear when they make a call. The operator receives calls and routes them to appropriate departments, as well as handling short questions and requests for assistance.