) Choose the correct options. Sometimes both answers are correct. 1 She's just run twenty kilometres. She may /must be exhausted. 2 You musty can't be Luke's brother- nice to meet you. 3 I'm not sure whose bag this is, but it could/might be Kate's. 4 Tidy up your room – the guests must /might show up any minute now. 5 Your parents may/might be right-perhaps it is better to choose a school nearer your house. 6 It could /can't be her birthday today- I'm pretty sure she had a birthday party last month. 7 Whatmight/ must be the reason for her bad marks? 8 Your computer could/might have a virus, perhaps that's why it's so slow.