The U.S. national version of the International Reference Alphabet is referred to as __________.

What key combination helps to secure the logon process?

A. Windows+R B. Ctrl+Shift+Esc C. Ctrl+Alt+Del D. Alt+F4

A full binary tree with height 4 has ______ nodes.

a) 7 b) 8 c) 15 d) 31