Answer and explanation:
The purpose of using dashes in this excerpt is to set off an appositive sentence that contains commas. An appositive sentence is a structure that offers further information on something mentioned before it. Appositives can usually be set off by commas but, when they are long and present commas in their own structure, they are set off by dashes.
In the excerpt we are studying here, the appositive "-so-called because they used to, like, DECLARE things to be true, okay, as opposed to other things are, like, totally, you know, not-" is a very long one and full of commas. It is supposed to offer further information on what declarative sentences are.
A source that is a trustworthy authority on a subject is a credible source.
I would try to use attractive descriptive words, such as lush or shining, something to captivate their memory. If I had any good stories to tell about the place I would want to focus on those, since stories make them imagine themselves in that place and situation, possibly making them want to go. Finally, I’d show them any pictures that I took to really capitalize on the beauty or charm of the place I’m talking about.
