中国大学MOOC: The newly elected president was popular among his people for his dynamism and ______.

Such changes are also indicators of economic dynamism and [color=#ff3853]demographic[/color] expansion. A: adj. 关切的；体贴的 B: adj. 空的；无人的；空虚的 C: adj. 人口结构的；人口统计的 未知类型：{'label': 'source', 'content': '柯林斯词典', 'isMemberControl': 0, 'type': 181}