ответить на вопросы 1)how long have you been using this book? 2)how long have you been studying english? 3)how long have you been learning english ? 4)how long have you been working on this lesson? 5)how long have you been sitting in this room?

1) I have been using this book for two weeks.
2) I've been studying English for 6 years
3) 2 и 3 вопрос одинаковый. 
4) I'm working on this lesson for ten minutes
5) In this room I sit an hour