It means he will pretend to be mad, in order to plot his revenge and act upon it. "Antic" used to mean "madcap", "bizarre", which suits Hamlet because he doesn't want to be taken seriously until he proves to himself that Claudius is really his father's murderer, and Gertrude complicit. Hamlet goes on with his plan and does it so well that we, as spectators, are never 100% sure whether he is faking his madness or if it really grabbed hold of him.
He built a new tea shop to attract more customers.
The second one is correct because Lady Macbeth speaks to Macbeth privately in scenes 6-7 (I believe) of Act I and tells him that "the false face hides what the false heart doth know", which is basically telling him to make Duncan continue to think he means no harm, but to carry through with her plan of murder.
The correct answer is <span>very simple language
Hemingway is famous for this. Sometimes he could write entire passages with no words larger than 2 syllables.</span>