In my opinion, they do not only reveal what will happen, but also manipulate events. When Macbeth approached the witches, they could have concealed the truth from him and just let the events unfold, but they didn't do it. They told him about the prophecy, thus initiating the events that soon followed. If they hadn't told him the truth, Macbeth might have never killed Banquo, Duncan, and the rest in order to become king. So yes, they manipulated events and caused a great tragedy.
Well I see it as an A for effort. But in in all fairness if you lost the game you shouldn't really be a sore loser because of it. In football games the people keeping score don't give the points the other team that lost because "they tried". I was on the cheerleading team and the other girls won nationals but I thought it was unfair because we all really tried our hardest and the thought we should get extra points. But I know that's totally ridiculous now.
