1. A structural, instrumentality-based system for presenting and teaching, exclusively, plural, different, selected, short-vowel sounds in the context only of associated short-vowel-sound words which, correctly spoken, present, in terms of vowel sounds, solely those sounds, said system comprising for each, selected, short-vowel sound, an associated and dedicated, foreground/background pair of operatively connected, relatively rotatable, word-fragment carriers, committed, and limited, to the teaching of the short-vowel sound of but a single vowel, and including a foreground carrier carrying but, and limited to, a single, first-category, readable, word-ending word fragment having, under all circumstances as the first letter within it, the single vowel whose short-vowel sound is associated with the carrier pair, a window disposed in said foreground carrier adjacent, and readably to the left only of, said first-category word fragment, sized to reveal, at any given time, but a single, background-carrier consonant, and a background carrier which carries a plurality of second-category, individually-window displayable, single-consonant-only, readable, word-beginning word fragments each dedicated to working in juxtaposed, proper-word teaching cooperation with the single, word-ending, word-fragment which is carried on the associated foreground carrier, and each displayable, via selected, relative-rotation, relative angular positioning of the two carriers in the pair, and one only at a time, through said window, to combine readably with said first-category word-fragment to form therewith a complete, proper, short-vowel-sound-only word which is correctly pronounceable utilizing the associated short-vowel sound, said paired and associated foreground and background carriers, and their respectively carried word fragments, each being constructed whereby every window-revealed background-carrier word-fragment in relation to every thereby cooperatively created combination of associated foreground-carrier and background-carrier word fragments, forms, with the juxtaposed foreground-carrier word fragment, a proper, short-vowel-sound word.