The dependent clause always has a subject and a verb. However, the clause can't stand by itself because its not a complete thought.
Conjunctions can be remembered as FANBOYS- For, And, Nor, But, Or, Yet, So. They always connect two independent clauses and all have less than 4 letters.
Its the third sentence,because a plural word hast to have a dash, not a space/
I don't have the book so I can't give a line of evidence but Atticus was all about teaching Jem and Scout those little life lessons without them even noticing so this instance was one of those little lessons he gives them. Hope this helps :)