Complete the sentences choosing present progressive or present perfect progressive.
1 Sally is in the classroom. She (air) __________ the room.
2 Chris is tired. He ( clean ) __________the school yard all day.
3 Jenny and Sarah are happy. They (sunbathe) _________ since morning.
4 Dad is busy. He (build) _________ a nestling box.
5 Our friends can't come with us for a walk. They (watch)_________an interesting film.