Adress - город, страна, либо полностью - №дома, город, страна)
Число
Dear Helen,
I was glad to get your letter! Sorry I haven't written for so long but I had a lot of homework.
I so sad that you have problem such a putting a lot of weight. I don't have the same problem before. But I think you are better to ask parents. Or try to go to the gym. Do morning exercises every day. I amn't sure that to keep to a diet is good. Anyway you should consult to the doctor. How much have you put on? What think your parents? Are your classmates laughing at you?
Well, I'd better go now as I promised my mother to help her. Write back soon!
Best wishes,
Имя.