A teacher is someone who input knowledge into students' minds,arouse students' inventive thinking and stimulate students to succeed. And parents are the first teachers of us, they stay with us the longest, and they are considered the best teachers of us. But personally, I don't think we can generalize and say parents are the best teacher, although ideally they are meant to be great teachers. I think some parents have problems to raise the children, and the surroundings around children influence them a lot. As individuals, parents more or less have some bad behaviors. Some parents abuse the children which is a serious problem. Society has to protect the children from the parents. Sometimes, an official of children protection center visits the parents, and persuade not to violate them. In the worst case scenario, parents and children have to live separately. Parents are not teachers any more in this case. It is even more worse that all children tend to unconsciously or subconsciously replicate every behaviors including bad ones from their parents.