Do boundary classes have a multiplicity with the control classes? And what about the control classes with the entity classes?

for a SE class I have to create a specification diagram. Some questions came to my mind when creating this diagram. These are the questions: 1. Do boundary classes have a multiplicity with the control classes? If so, is it (always) 1 -- 1? 2. And what about the multiplicity between control classes with the entity classes? If so, is it (always) 1 -- 1..*? 3. Do boundary classes have attributes?