Choose the correct words. Sometimes there is more than one correct answer. 1 A: Is Isaac coming to work tomorrow? B: He's not sure. He may / might / must stay at home if he isn't better. 2 A: My doctor didn't know how to treat my flu. B: What? He's a doctor - he could / should / ought to know how to do that! 3 A: According to this article, too much red meat is very bad for your health. B: I'm sure that can't / might / must be true. 4 A: Where are all the volunteers? B: They should / could / can't be busy with the animals. Maybe they're feeding them. 5 A: I think Bella is going to the gym. B: She may / ought to / can't be going to the gym because her gym bag is still here. 6 A: Dale is still waiting for Sam to arrive. B: That's strange. Sam left hours ago so he could / might / ought to be there by now.