Question

For questions 15–17, identify whether the group of words is a sentence or a fragment.

15. Rotating back and forth aimlessly. (1 point)
sentence
fragment
16. The fan blades spun rapidly, generating a strong cool breeze. (1 point)
sentence
fragment
17. The sound of ringing bells marked the end of a beautiful wedding service. (1 point)
sentence
fragment

Answer 1

One of these is a fragment.

And that's #15.

"Rotating back and forth aimlessly."

Do you see how that sentence doesn't have a subject?
We have no idea WHAT is "rotating back and forth aimlessly."

The others, #16 and #17, both have a subject and a verb. They're all sentences.