It is love that makes the world go round. And it is also love that has such power to overcome all difficulties. So we say: “Love will find a way.” As smile is a facial expression showing pleasure,
--- Marry is in hospital. --- Oh, really? I _______ know. I _________ go and see her. A. didn’t; am going to B. don’t; would C. don’t; will D. didn’t; will
＝(1,2)，
＝(4,1)，
＝(0，－1)，则△ABC的形状是______________．