True allergies to cow's milk are relatively uncommon. Only 2 to 3 percent of children are allergic to milk, according to the AAP, and almost all of them outgrow it by age 3. (Learn the difference between a milk allergy and lactose intolerance .).
The underscore [ _ ] (also called underline, underbar, low line, or low dash) is a character that originally appeared on the typewriter and was primarily used to underline words.
Alternate voice. Double underscores surround a span of text in an alternate mood or voice, a technical term, an idiomatic phrase from another language, a thought, a ship name, or some other prose whose typical typographic presentation is italicized.