Stating that "7,000 people watched the night Frankie Nelson set her 18-hour record” most develops the central idea that the introduction of the bicycle brought with it many changes.
indoor track racing was more popular than outdoor racing.
female cyclists were more competitive than male cyclists.
bicycle racing was a popular sport in the 1880s and 1890s.

bicycle racing was a popular sport in the 1880s and 1890s.

Explanation:

As a result of stating that "7,000 people watched the night Frankie Nelson set her 18-hour record”, the writer is trying to make it known that a lot of people were interested in watching the event.

Therefore, the thing that most develops the central idea is that bicycle racing was a popular sport in the 1880s and 1890s

the purpose of a nonfiction text is to give the text a rap up. for example, when i say : frogs are interesting animals is an ending. then when i say: frogs are unique in different ways. that is an intro.