chinese proverb says, being teacher for one day, being the father all life long. we can see that teacher is the same important as our parents, actually the teachers' words and actions affect the students for one life time.
so a good teacher should play different roles, the good teacher shall be very patient to deal with different student, every student is one free individual, owns different experience and ideas, teacher has to get close to them and share with them somethng, with different student at different times, there is lots of difference in the communication. finally the teacher gets closer to the student and open his heart, so a good teacher is like friend, he shall be fun. each student is the same important in teacher's mind, the teacher shall take care of all the students, like the parents, the parents will never discriminate the children. so a good teacher shall be equal.