Which sentence uses refrain as a noun? the flight attendant requested that the passengers refrain from smoking. students should refrain from using their cell phones during the lecture. experienced audience members refrain from clapping until the end. the haunting refrain stayed with the audience long after the show ended.

The last one, "The haunting refrain..."

The sentence that uses refrain as a noun is D. The haunting refrain stayed with the audience long after the show ended.

Explanation:

Refrain as a noun -a word that refers to a person, thing, place, event, etc.- can be defined as "a regularly recurring phrase or verse in a poem or song". In sentence D, refrain is used in this sense.

On the other hand, as a verb, refrain means to avoid or stop yourself from doing something. Sentences A, B and C use refrain as a verb.

- "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."

the autor of the text is bringing the point that one achievment of the president john f. kennedy was a success and this caused the next president to use a similar idea. the purposefor the use of the quotation in the text is to support the idea that peace corps was a result of the president's call. in this case, the quotation is presented as part of the writing and does not stand on its own.

answer a.