Answer:
Are you speaking about the actors or the audience? If you are talking about the actors- never! It would be highly irresponsible to fall asleep at your job. If you are talking about the audience- I suppose you can fall asleep whenever, but it would be disrespectful to the actors (unless you are watching the film version).
Answer:
The term that you are looking for is Imagery.
Hope this helps!
The dependent clause of the sentence is "If we are going to make it to the movie on time," because it depends on the next part of the sentence to make sense. Without the next half of the sentence, the clause left alone wouldn't make any sense. The other clause is independent, meaning that it still makes sense when it stands without the dependent clause.
