Choose the best modal verbs to complete the sentences.

Choose the correct option.

It [must|might|can't] be very crowded in Rio de Janeiro now. The biggest festival has started there.

He [must|can't|may] be late for class, but I'm not sure. He got up twenty minutes ago.

I can't find my iPhone. Someone [can|must|couldn't] have stolen it while I was on the crowded bus. The last time I took the bus, I got robbed, too.

Emily [must|might|can't] be in Italy, we are meeting today.