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.
You can look at the words in front and behind it, because they refer to this big word. You may find a synonym of the word or a close reference. So for example in this sentence: I was excited and ambitious to learn about cars today. So this is a easy example. You can use exited to define ambitious if you dont know what ambitious means.
System is a kind of program that evaluate leaderships