Copernicus should be the topic, and the central idea should be how he came up with the heliocentric theory. I hope I helped, please tell me if I am incorrect or if you need more help!
Answer:
<em> by using descriptive phrases to explain difficult ideas</em>
Explanation:
The Big bend can be described as a proposed skyscraper which is to be constructed in New York City. The proposal is most known for its distinctive U-shape, which would make it the longest building in the world,though not the tallest, if it were built. The Big Bend is a curved, 4,000 foot-long skyscraper planned on Manhattan's Billionaire's Row. Although the author uses descriptive phrases to explain the ideas behind the big bend however, it is very unlikely that the project will ever be built.
Im pretty sure is the last one
I think it might be B if not sorry