Sprung rhythm involves using . a. varing numbers of both stressed and unstressed syllables. b. a fixed number of unstressed syllables and varying numbers of stressful. c. varying numbers or unstressed syllables in a fixed number of stressed syllables

- "the basic difference between keywords and subjects is that subjects (or "subject headings") have been predetermined, while keywords have not. a keyword is an easy place to start because you can use any word that seems to fit your search; this is called "natural language" searching."

this is a good question! i'll do some research and come back when i have the answer!