Students insulted

A student has been absent for days after her final year exams.
My friend is curious about it. He inquires about her whereabout from her classmates.
He is informed that she doesn't like to go to school beacause she doesn't like a teacher.
She says the teacher always looks domn upon her, teases her and says sarcastic words to her. The teacher also passes bad comments on her academic results.
She feels insulted and not respected by the teacher. She wants to escape from the teacher.

As a teacher, he/she must have the patience and caring spirit in their teaching career. They must have the positive attitude to educate children without any biases. They must try all the effort to help the children to understand the academic materials. They must also try to understand the children's problem in learning processes.

Are they slow learners?
Are they equipped with all the necessary tools for learning?
How well is our teaching?
Can they follow the teaching?
Are we too enthusiastic to impart teaching materials?
Do we care about their capbilities?
Do we care only about results?
What is our right to look down upon them?
Can they comment on our teaching?
Can they look down upon us?
Do we deserve respect from them?

I wonder.