Macbeth is both excited and fearful after hearing the witches predictions about his future because the witches told Macbeth that he would be king, and he is worried about his role in making the prediction come true.
if you look at the last word it'll tell you, "go" and "grow" rhyme since they rhyme they will both be an A, then "sky" and lie" rhyme since they don't rhyme with A we will make it a B.
