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.
An operand is a constant (text or number) or cell reference used in a formula. An operator is a symbol that indicates the type of calculation to perform on the operands, such as a plus sign (+) for addition. Table 4â1 shows the different mathematical operators you can use in formulas. Consider the formula =B3+5.