3. [30 pts) Fill in the blank. 1) Given a sequence, we need to frequently access its elements randomly. Which one you will choose, array or linked list? _Ans: 2) Given a sequence, we need to add or delete elements frequently. Which one you will choose, array or linked list? Ans: 3) In a single linked list, each node contains elements. They are In a double linked list, each node contains elements, which are