What is the definition of Eligible Blood Cells?

Eligible blood cells? Oh boy, let's dive into the world of blood! These are the superheroes of our circulatory system, specifically white blood cells (WBCs) and red blood cells (RBCs). WBCs are the body's personal bodyguards, patrolling for those pesky invaders like germs and viruses, while RBCs are the delivery drivers, carrying oxygen to all the vital organs. They're so crucial that if you don't have enough of 'em, you might start looking like a zombie or a runaway rocket.

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Example sentence: "The new blood donation drive only accepts 'eligible blood cells,' which means if you're carrying a bunch of old, stale, or even just expired cells, you might just be the perfect candidate for a 'cell-freeze' party."