Final answer:
A Venturi constriction is the narrow tube with two prongs that delivers oxygen flow. It is commonly used in carburetors and aspirators, as well as in medical devices for delivering oxygen flow.
Step-by-step explanation:
The rather narrow tube, with two prongs that fit up into the nares, that delivers oxygen flow is a Venturi constriction. A Venturi constriction is a tube with a narrow segment designed to enhance entrainment. It is commonly used in carburetors and aspirators, as well as in medical devices for delivering oxygen flow.