This document should help you understand more and explain!
http://file.scirp.org/pdf/CE20120200003_78369835.pdf
Hope this helped!
:)
Answer: One author claims that dogs bred to be tiny may have weak nerves
Explanation: The research word "claim" in this sentence is used correctly, and not to mention the fact that it is more likely for this word to come from a reliable source, such as a person that has written a book at least <em>once </em>in his or her life. (I've done this quiz).
