题目

抛物线y=-2x2+4x+3的顶点坐标是（ ）(A)(-1，-5) (B) (1，-5)  (C)(-1，-4)  (D)  (-2，-7)  答案：B 解析:略 I can’t decide to choose which of them to ________.A．make a friendB．make friends C．make a friend withD．make friends with