I'm sorry to tell you that I must give up this job.I hadn't done this job very well.I feel so sorry about this.
Teacher,I beg your pardon,but I have no choice.I feel tired and I think there must be someone who will do this job much more better than I do.
I love this job but I don't think I meet with this job.Job is a good job,but I'm not a responsible representative.
Though I don't want to continue this job,I won't give up english.I'll try my best to study ehglish.If one day,teacher think I still have the ability to be your representative,I would be glad and thankful .And if at that time ,I would be cheerful to be your representative again.
Thank you for your comprehend
your student:
time：
（現場發揮,如有語法錯誤,請原諒）