I mean who teaches or those who convey knowledge to students, teaching of teachers. The heavy duty is less than the one who is will grow knowledge and good of society, the "teacher" would be dedicated physical and mental than the biological parents. In one"s life. In addition to the parents, which is our first teachers. "", the children will live on in society. It is necessary to have a "teacher" to bestow knowledge To form into a profession in the future.