题目

---Mary told me she would ______trying． ---Really? I'll try my best to ask her to ______such foolish ideas． A．pick up, give up                                  B．put away, give up C．give up, put away                               D．give up, pick up 答案：C如图，是二次函数y=ax2+bx+c（a≠0）的图象的一部分，给出下列命题：①abc＜0；②b＞2a；③a+b+c=0④ax2+bx+c=0的两根分别为-3和1；⑤8a+c＞0．其中正确的命题是______．