____________________ is a modulation technique that involves a four-bit code in which eight phase angles have a single amplitude, and four phase angles have double amplitudes.?

________ is duplication of data stored in two or more tables

Fill in the blank(s) with correct word

When working with a menu-driven program a case structure's _________ section can be used to validate the user's selection.

Fill in the blank(s) with the appropriate word(s).