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 ​

1. You shouldn't leave your rubbish on the beach.

2. Someone must have stolen the paintings from the art gallery.

3. You didn't need to ask Paul to come and help us.

4. Louise may have drawn the dragon on the wall.

Explanation:

Explanation:

1.You shouldn't have left your rubbish on the beach.

2.Someone must have stolen the paintings from the art galler.

3.you need not ask Paul to come and help us.

4.Louise may have drawn the dragon on the wall.