In ________ implementations, the legacy system and new system are used concurrently

A ________ keeps your computer safe by determining who is trying to access it

A) gateway B) hub C) firewall D) switch

A ____ is a list in which each element contains a key, such that the key in the element at position k in the list is at least as large as the key in the element at position 2k + 1 (if it exists) and 2k + 2 (if it exists).

A. hash table B. hemp C. heap D. pile