The school full of alien teacher

Maybe today is a wonderful day in my life because I get up early this morning so i decided to go school early and do my homework. When I got there , I had a problem with math exercise so I went to the teacher room to find Mr. Barnaby. I opened the door and was very very surprise to see that my teachers were all aliens. They are all in the same size and face .And I ask them which one is a math teacher of my lovely and brilliant class name Mr.Barnaby ? =='' And one of all aliens was answer yes it me . When I hear that I was very happy because I can find my math teacher. In only 2 second he introduce himself to me that he name is Barnaby he was taught here for 2 year and a half . he was 99 years old. Suddenly I tell him to stop and I ask him that can I ask you now ??? -.- He said that OK what your problem can I help you "_" He smile with a big mouth . I ask him that this chapter 2 in exercise 5Z  I don't know how to solve it can you help me ??? He said that it OK I will help you. Let me see . He take my homework and solve it for me maybe 2 hours . And then he walk to me in order to give me back my homework . I was very happy when I see him but he told me that sorry I can't solve this because it such a hard exercise that I ever met before . And now I won't teach math anymore . I already change to teach physic at stupid and silly class . @.@'' And I shout at him " WHY YOU DIDN'T TELL ME ABOUT THIS ??? He not even had an alien face size and he also had alien brain. :'(