Add the phrase that completes the thought in the underlined sentence don’t worry she said grinning I have a plan

To solve your problem

Explanation:

100% correct I did it correct

- "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."