Which statement about quotation marks is true?

i. quotation marks set apart short quotations.

ii. typically, a direct quotation requires three quotation marks.

iii. commas used to introduce short quotations appear outside the quotation marks.

- "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."