1) Tanya is fixing a pumpkin on the sticks, isn't she?
Is Tanya or Natasha fixing a pumpkin on the sticks?
2) Robin is decorating the room, isn't he?
Is Robin decorating the room or the flat?
3) Robin and Dima are making a mobile, aren't they?
Are Robin and Dima making a mobile or a model of ship?
4) Lena is cooking a Halloween treat, isn't she?
Is Lena or Sveta cooking a Halloween treat?
5) Katya and Lena are carving a pumpkin, aren't they?
Are Katya and Lena carving a pumpkin or a carrot?