Question

read the dictionary entry.
re • frain ri - freyn

1. (verb) to resist doing something
2. (noun) the chorus of a musical piece

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.

Explanation:

In the first three sentences, "refrain" is used as a verb (to resist doing something). In the last sentence, "refrain" is used as a noun (the chorus of a musical piece).

Answer:

The haunting refrain stayed with the audience long after the show ended.