What is a sentence fragment?

Which of these is NOT a punctuation option for the end of a sentence?

Which of these groups of words is a sentence fragment?

Is this a complete sentence? "Running is tiring."

How many sentences are contained in this group of words? "The students went to the classroom they got out their book, then they started to read.

The beautiful bird flying high above the trees. <-- is that a fragment, sentence, or run-on?

I got home late, washed my face and fell asleep. <-- which is a good way to fix this run-on sentence?

The store was out of donuts, so I bought a bagel. <--is this a fragment, sentence, or run-on?

True or False: a subject is always a noun or pronoun

Does the following group of words have both a subject AND a verb? The family thought they heard burglars.

Is the following group of words a fragment, complete sentence, or run-on sentence? After Amy sneezed all over my dinner.

Does the following group of words have both a subject AND a verb? Running on Mondays is rough.

Does the following group of words have both a subject AND a verb? In the dark of night.