Ответ:
1) Why have you been sitting here for 30 minutes? We have been waiting for our friend Mike.
2) He has been writing that letter since he got home.
3) Why have you got paint on your hands? – I have been painting my bedroom.
4) She hasn't been feeling for a couple of days. She’s got a temperature and a headache.
5) I have been going to judo classes for five years.