Nobody _________ (know/knows) when he will arrive. We _________ (must find out/find) where to put it. I _________ (shall show/show) you how to operate it. Jack _________ (cannot/could not) decide what he should do next. I _________ (can’t/could not) imagine why she has behaved like that. Can you _________ (tell/told/tells) me where he lives?