我吸烟被学校抓住,而且以前表现不好,急于求一份拿英语写下的保证书

I am small time, I very naughty, often the mother angry. Now, I was a middle school student, also always make mistakes. Due to the great pressure of the present study, I found that smoking is a good relieve pressure Drive. Coupled with students around smoking, as my akrasia poor, has unwittingly started smoking.
I should not smoke. Should not smoking in schools. Local schools are learning in schools should study well. Smoking harmful physical and mental health, I have quit smoking. Take my energy into the study. Please forgive my teacher. I must correct our mistakes and be a qualified secondary school students.

my respectful Mr Qu,since my smoking,bing you lots of trubble,i decide not to smoke in the future 我只能帮你这么多，而且可能有很多错误，西西