Dear Peter,
Hope you are fine. It was great to get your letter. Speaking of your questions, I should say that my summer was really fantastic. I went to London with my friends and we had a really good time together. I saw lots of famous sights in this city. This city is really amaing! Now I undertand why is it famous and well-known amoung tourists, especially amoung young people and teenagers. Was your summer good too? Speaking of your birthday, what present do you want? Are you going to have a party? If yes, where and how many people are you going to invite? That's all for now. Let me now about the date. I'm looking forward to your letter.
Best wishes,
Anna.