Teaching!

After teaching for long time, there's no students were saying that I did not prepare to the class. I am a hard worker and I always prepare to the class. Teaching junior ones are harder and I have to raise my voice and more than that they do not even appreciate what I am doing in the classroom. I do not know what to do and I do not want everyone saying that they are not even learning. I want everyone learn in my class but at the same time, I need them to understand that I do work very hard.