Complete the sentences with must, might or can't and the correct form of the verb in brackets.

1. I'm absolutely certain that Jo isn't going on the march. In fact she _______ (leave) the house because she feels really ill.

2. Julie sometimes likes to go into the office on Saturdays, so she _______ (decide) to go there this morning. I'm not sure though.

3. Who knows where Paul is? He never tells me what he's doing. I suppose he______ (go) away for the weekend.

4. My boss _______ (take) the afternoon off. He looked really ill this morning.