Final answer:
An MEF usually has three MEUs assigned to it, prepared to deploy globally as a quick reaction force, complete with self-sustaining combat and support elements.
Step-by-step explanation:
Each Marine Expeditionary Force (MEF) typically has three Marine Expeditionary Units (MEUs) assigned to it that deploy throughout the globe. The MEUs are a quick reaction force, designed to respond to any emergency within a 6-hour timeframe. These units are self-sufficient, with their own tanks, artillery, and air assets, making them a formidable force capable of responding to a variety of global situations and crises.