Laura was on fire that night at the club. She was playing and singing like she never had in the past—for once she didn’t feel self-conscious. She was letting it all go, holding back nothing. The crowd loved it. When it was over, the club owner asked her to come back next week.

quite an interesting way to teach topic sentences, because the answer to this question is the best definition of a topic sentence that one can present, it is as if answering the questions taught you how to do it, this is some real teaching, it is terribly well-done.

the topic sentence in this paragraph is:

topic sentences writers stay on track and keep a paragraph from becoming an aimless collection of sentences about an idea.

which incidentally tells you what a topic sentence should be.

what do you mean