What type of language convention has the author used to separate the declarative sentence from the disruptive phrase in this excerpt from "totally like whatever, you know? "? "declarative sentences—so—called because they used to, like, declare things to be true, okay, as opposed to other things are, like, totally, you know, not— have been infected by a totally hip and tragically cool interrogative tone? " commas question mark capitalization em dashes