Dummy nodes are used to simplify list processing by eliminating some “special case.” 1. What special case is eliminated by a header node in a linear linked list? 2. What special case is eliminated by a trailer node in a linear linked list? 3. Would dummy nodes be useful in implementing a linked stack? That is, would their use eliminate a special case? 4. Would dummy nodes be useful in implementing a linked queue with a pointer to both head and rear elements? 5. Would dummy nodes be useful in implementing a circular linked queue?