cc pourriez vous maider svp 3 et 5 svp

exercice 3 : 
1- he has been practising the piano for 2 hours. Hasn't he?
2- they have started listening to the rock at four o'clock.
3- he hasn't been learning guitar for long long. Hasn't he?
4- he has started surffing at midday.
5- they have been talking on the phone for half an hour.

exercice 5:
1- do you play the oboe?
2- how long do you practise it a day?
3- since when do you practise it?
4- which one you have been rehearsing? 
5- how long you have been rehearsing it? 

( je suis pas très sûr de mes réponse, j’espère que je t'ai aidé )