My mother tells me that I__________(can/could)go to bed as late as I want. 2.As soon as she opened the door I_________(can/could)see something terrible had happened. 3. It was dificult to understand what the scientist said about the outer space. I was sure _________ (can't/couldn't). 4.I have no idea where my brother is living now.But I know he_________(can't/ couldn't) be at the North Pole.