One possible version:

Dear Stella,

     I was very glad to receive your e-mail on Sept. 23,2011. At your

request, I'll tell you something about my school life.

       This year, I'm in Senior 3 and I have six subjects to learn every day.

School hours usually begin at 7:10 a. m. and end at 6 :00 p. m. As you can

see, we are making full use of every minutes preparing for the coming

NMET. Though time is precious,  I try to do some sports or do some

reading in the school library after class. Sometimes I even go to join the

School English Corner, where I can practice oral English with some

foreign teachers and other students.

     In my opinion, "Work while you work, play while you play.",

which is the way to be cheerful and gay. Only in this way can we

guarantee the efficiency of our learning. On the other hand, it is time our

government thought about our education reform to make sure that every

student learns happily and efficiently at school.

      I'll appreciate it if you can tell me something ahout your school life

as well. I'm looking forward to it.

     With best regards.

            Yours,