1. An array uses less memory than a singly linked structure when: a. Less than half of its positions are occupied by data b. More than half of its positions are occupied by data

2. When an array runs out of memory to hold data, it is best to create a new array that: a. Has one more position than the old array b. Has twice as many positions as the old array

3. The worst-case running time of an insertion into a singly linked structure occurs when you insert: a. At the head of the structure b. At the tail of the structure

4. A doubly linked structure allows the programmer to move: a. To the next node or the previous node from a given node b. To the next node only from a given node