13、运行下列Python代码，最后a中存储的内容是 ( )
a ="钢铁侠”"绿巨人”"蜘蛛侠"] a.append(”黑豹”)
[”钢铁侠”,"绿巨人","蜘蛛侠”]
["钢铁侠","绿巨人",蜘蛛侠”,"黑豹"]
["钢铁侠”"绿巨人”,"蜘妹侠”"钢铁侠”]
["钢铁侠”]
