Bill is an English boy. He is twelve. He lives in China with his family. There are four people in his family. They are his father Jack Cliton, his mother Catherine and his little sister Abby. He has a yellow dog. Its name is Barbi. His father is mending his bike. What is Bill doing? Ah, he is doing Chinese homework. He can't speak Chinese very well. But he loves Chinese very much. Bill's father works in middle school. He is an English teacher. His mother is in a TV factory. Bill and his sister go to the same school.

“兴国安邦”的“安”字用部首查字法查____部再查____画。用音序查字法查大写字母____它的读音是____。“安”在词语中应选以下第____种解释。①身体健康。②不出事故，没有危险。③稳定。④装置，组合。用第②种意思组一个词____。

掌握朝代的更替是了解历史发展线索的重要方法之一.因为水患和政治动乱,商朝曾几次迁都,一直到商王盘庚迁都到殷,都城才稳定下来.后人称商朝为殷朝. 盘庚以后,商朝统治区域不断扩展,成为当时世界上的大国.
请回答：
（1）在我国历史上,商朝是在灭了哪个朝代的基础上建立起来的?
（2）商朝灭亡后,我国进入什么时期?这时期为了巩固统治,实行什么制度?有何作用?
（3）到了战国时期,新兴的地主阶级先后在各国掀起变法运动. “治世不一道,便国不法古”是谁说的?请你说出他变法的主要内容.(至少两点).
（4）战国时期,各国经过变法,我国什么社会形成了?