1.It wasn't a good idea to leave your rubbish on the beach (should't)
You __________________
2.The most logical explanation is that someone stole the paintings from the art galler. (must)
Someone ____________________
3.It wasn't necessary to ask Paul to come and help us. (need)
You ______________________
4.I think Louise drew the dragon on the wall. (may)
Louise ____________________​