Помогите раскройть скобки, употребляя Present Perfect Continuous.1. John is in his

Помогите раскройть скобки, употребляя Present Perfect Continuous.

1. John is in his room, he (to sit) there since the morning. 2. For two hours now we (to talk) about it and we haven't come to any conclusion yet. 3. John, do you know where my bag is? I (to look) for it for half an hour and I can't find it. 4. Look, your brother (to dance) with that red-haired girl since she came into the room. 5. She (to teach) at school for twenty years.