"Got milk?" is an advertising slogan reminding people to buy milk by implying that it is a necessity everyone should have on hand.
A gallon of milk is a necessity that people have in their homes on any given day. In 1969 a gallon of milk cost 1.25.
The possessive form of the noun necessity is necessity's.
The plural of necessity is necessities.
Twitter is not a necessity.
necessity
necessity
Because it's high in protein, high in calcium, is loaded with vitamins and is relatively low in fat (even 'full fat milk' contains less than 5% fat.
necessity
Necessity.
The Necessity of Atheism was created in 1811.
Fort Necessity