Dear friend,
Thanks for your letter. My name is Ksenia. I'm eleven years old too. I live in Moscow with my mother and father. Actually, I have a cat. He is funny. My father works in emporium, and my mother is a teacher. I have no sisters and brothers.
I go to Moscow school. I’m in the fifth grade. My favorite subject is art. I like playing with my cat very much.
How are you? How is your Mum now?
Write soon,
Ksenia
(Личную информацию как город, возраст, класс можно заменить.)