So, where did I find my facts and figures? In lots of different places. Tracking down information about black holes was a little like tracking black holes themselves. It took research, questions, and lots of cross-checking to piece together something that made sense. Then again, it was a lot easier for me to track down information than it is for astronomers to locate black holes—thanks to high-quality Internet resources and helpful librarians, such as Jeffrey Mehigan and Debbie Batson. Luckily I was able to find what I wanted without special X-ray detectors. –A Black Hole Is Not a Hole,
Carolyn Cinami DeCristofano
Why does the author include this paragraph at the end of the book? Check the three answers that apply.
to show that it takes research to write an informational book
to show her appreciation to the librarians who helped her
to finish the book with a joke
to recognize the role of the internet in her research
to discourage others from attempting to write an informational book