Answer:
Peeta is strong and excellent at camouflage. More importantly, he is a link to Katniss, which the careers have targeted because of her high scores and popularity in the days leading up to the games.Peeta joins forces with the career tributes because they think he will lead them to Katniss.To keep the games 'exciting' they started fires in the arena.Katniss acts differently because she doesn't want to seem weak or look like an easy target. So she shows no emotions but fury towards the other tributes.The careers accept peeta because they want peeta to lead them to katniss.but peeta has a different plan, peeta joins the careers to keep them away from katniss.
