A:to stay
B:stayed
C:stay
D:having stayed
-- Tom, can you help me do some housework?
-- Sorry, mum. I to school.
如图是人们常见的几种动物,请分析回答:
王国维说:“欲观周之所以定天下,必自其制度始矣……封建子弟之制、君天子臣诸侯之制。”这里的“制度”应是( )