It is said that in the seventh century BC during the Spring and Autumn Period,Jie Zitui was a good official inthe Jin State,working for Prince Chong’er.When the Jin State was in great disturbance,Chong’er was forced to leave for other states with his faithful officials and servants,including Jie Zitui. For 19 years,Chong’er and his followers went through all kinds of hardships and difficulties.One day,Chong’er was actually starving and close to death.Jie Zitui cut a slice of flesh from his own leg and served it to his master,thereby saving his life.
It is said that in the seventh century BC during the Spring and Autumn Period,Jie Zitui was a good official in the Jin State,working for Prince Chong’er.据说在公元前7世纪的春秋战国时期，介子推是晋国的一名官员，效力于公子重耳。
It is said that，据说；其中It做形式主语，真正的主语是that引导的从句(ps:that后都是that引导的主语从句)；类似的还有：It is believed that，据认为 ;It is known that 众所周知;It is reported that 据报道......
When the Jin State was in great disturbance,Chong’er was forced to leave for other states with his faithful officials and servants,including Jie Zitui.当晋国动乱的时候，重耳被迫离开晋国带着他的官员和随从去往其他国家，其中包括介子推。
When the Jin State was in great disturbance，是when引导的时间状语从句；
be in great disturbance，处于极大的骚乱中；
be forced to，被迫；
leave for+地点名词，出发去某地；
For 19 years,Chong’er and his followers went through all kinds of hardships and difficulties.在19年时间里，重耳和随从们经历和各种坎坷和困难。
go through，经历；
all kinds of ，各种各样的；
One day,Chong’er was actually starving and close to death.Jie Zitui cut a slice of flesh from his own leg and served it to his master,thereby saving his life.一天，重耳几乎都快饿死了。介子推从自己的腿上割下一块肉给他的主子吃，从而救了主子的命。
One day，有朝一日; 有一天，总有一天；
be close to，濒临;接近，靠近;
thereby saving his life，此处是动词ing短语做结果状语。
It（形式主语） is said that （引导主语从句）in the seventh century BC during the Spring and Autumn Period, Jie Zitui（从句的主语） was a good official in the Jin State, working（伴随状语） for Prince Chong’er.
When the Jin State was in great disturbance（时间状语从句）, Chong’er（主句主语） was forced to leave（不定式短语作结果状语） for other states with his faithful officials and servants, including Jie Zitui. For 19 years（时间状语）， Chong’er and his followers（主语） went through（谓语） all kinds of hardships and difficulties（宾语）. One day（时间状语）, Chong’er（主语） was actually starving and close to death（谓语，系表结构）. Jie Zitui（主语）cut （谓语）a slice of flesh （宾语）from his own leg（状语） and served（并列谓语） it（宾语） to his master（补语）, thereby saving his life（结果状语，分词短语）.
翻译：
传说公元前7世纪春秋时期，介子推是晋国的一名贤臣，辅佐晋国公子重耳。在晋国动乱期间，重耳被迫带领忠心于他的官员随从等出逃到别的国家，其中包括介子推。重耳及其追随者在外流亡了19年，经历了诸多艰难险阻。一天，重耳就快饿死之际，介子推从自己的腿上割下了一块肉喂给重耳，救活了公子重耳的命。
从句：
主语从句：It is said that in the seventh century BC during the Spring and Autumn Period, Jie Zitui was a good official inthe Jin State, working for Prince Chong’er.
时间状语从句：When the Jin State was in great disturbance, Chong’er was forced to leave for other states with his faithful officials and servants,including Jie Zitui.
短语或固定搭配：
it is said：据说
the Spring and Autumn Period：春秋时期
work for sb.：为某人工作
be forced to do sth.：被迫做某事
go through：穿过、经历
all kinds of：各种各样的
close to：接近、濒临 【close to death：濒临死亡】
cut ... from：从……切下/割下……
save one’s life：拯救某人的生命