Choose the right verbs to complete the sentences.

Choose the correct option.

This [must|may|can't] be Nina! Her voice is completely different!

I'm not sure, but I think this film [must|may|can't] be based on a real story.

We do not believe you! You [must|may|can't] be right, but you have to prove it to us.

It [must|may|can't] be an original painting by da Vinci. It's definitely fake!

There's no doubt we [must|may|can't] win the drawing competition. We're the best in our school.

Susan [must|may|can't] be skipping classes today. Yesterday, she told me she wouldn't come.