Правильный ответ
When I arrive at the party, everybody (will be celebrating/will celebrate/is going to be celebrating). Some (will be dancing/will dance/are dancing). Others (will talk/ are going to be talking / will be talking). Then they (will be eating/will eat/are going to eat) pizza, and several people (will drink/are going to drink/will be drinking) beer. They always do the same thing.​