Dear [имя друга по переписки],
Thanks a lot for your email. I'm glad you're OK! Sorry I haven't answered earlier but I was really busy with my school.
In your message you asked me about holidays (тема письма – смотрим в задании: Subject: Holidays). Well, You know.
I've got to go now! It's time for my favourite TV show.
Write back soon!
Yours,
Kate
Ответ: Данное письмо составлено на основе предложенных фраз и структуры.