Dear Tony,
I received your letter two weeks (1) . Please forgive me for not writing to you sooner. I haven't had much time to write (2) I've (3) very busy moving into a new office in downtown Toronto.
In your letter, you (4) me how you could improve your marks at school. Well, first of all, you must make sure that you understand (5) you are studying. Just memorizing things without understanding them is useless. So always pay (6) to what your teachers say in class and don't be afraid (7) asking questions. Besides you'll need to use English quite a lot (8) you get older. So now, while you are in secondary school, you should try to improve your English. In my opinion, if you want to have good written English, you have to read (9) much well-written English as possible. To improve your listening skills, you can watch English-language programmes (10) televisions as often as you can. Well, it's getting late, (11) . I'll stop here. Give my love to your parents and write soon.