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.
Chemicals or energy is injected as required for displacement and for the control of flow rate and flow pattern in the reservoir, and a fluid drive is provided to force the oil toward a production well.il means crude oil or condensate. Operator means the individual, company, trust, or foundation responsible for the exploration, development, and production of an oil or gas well or lease.