Horatio asks the apparition four times to speak to him. What three reasons does Horatio give the ghost as to why it should speak to him?

At first, when the ghost refuses to acknowledge him, Horatio commands him to speak. Later, at the end of Act One, Scene One, Horatio wants to know if the ghost has some deed he needs done, so he can do it..... if there's something it knows about the future of their country, so that they might avoid it..... or if there is treasure, a secret that makes him restless..... something they could find and provide him rest.