We each have a memory（记忆力）. That's why we can still remember things after a long time. Some people have very good memories and they can easily learn many things in a short time, but some people can only remember things when they say or do them again and again. Many of the great men of the world have got surprising memories.

    A good memory is a great help in learning a language. Everybody learns his mother language when he is a small child. He hears the sounds, remembers them and then he learns to speak. Some children are living with their parents in foreign countries. They can learn two languages as easily as one because they hear, remember and speak two languages every day. In school it is not so easy to learn a foreign language because the students have so little time for it, and they are busy with other subjects, too.

    But your memory will become better and better when you do more and more exercises.

    Life is not easy, so I'd like to say “When anything happens, believe in yourself.”

    When I was a young boy, I was too shy to talk to anyone.My classmates often laughed at me.I was sad but could do nothing.Later, something happened, and it changed my life.It was an English speech contest.My mother asked me to take part in.What a terrible idea! It meant I had to speak before all the teachers and students of my school!

    “Come on, boy.Believe in yourself.You are sure to win.” Then my mother and I talked about many difficult topics.At last I chose the topic “Believe in yourself”.I tried my best to remember all the speech and practiced it over 100 times.With my mother's great love and encouragement(鼓励), I did well in the contest.I could hardly believe my ears when the news came that I had won the first place.I heard the cheers from the teachers and students.Those classmates who once looked down on (瞧不起) me now all said “Congratulations!” to me.My mother hugged me and cried excitedly.

    Since then, everything has changed for me.When I do anything, I try to tell myself to be confident and I will do a great job.This is true not only for a person but also for a country.

根据短文内容，回答下列问题。

（Ⅰ）若c²=a²+b²﹣ab，求角A、B、C的大小；

（Ⅱ）已知向量 $\overrightarrow{m}$ =（sinA，cosA）， $\overrightarrow{n}$ =（cosB，sinB），求|3 $\overrightarrow{m}$ ﹣2 $\overrightarrow{n}$ |的取值范围．

元代修史，朱熹及门人弟子被列入《道学传》，而陆九渊等人则被列入《儒林传》。明代，道学之名逐渐被理学取代。到清代，陆九渊被列入《理学传》而不列入《儒林传》。促成这一变化的主要因素是（  ）