Read this excerpt from "Mad Cow, Furious Farmer." A prion is a piece of protein very similar, but not identical, to other proteins in the brain. It is a little bit squishy and maybe a little sticky. If it manages to burrow into a corner of the brain, it will slowly bend and break all the proteins nearby, carving sponge-like holes all over the brain. These holes are what give the disease its official name: bovine spongiform encephalopathy, or BSE. "Bovine" means having to do with a cow, "spongiform" means having sponge-like structures, and “encephalopathy” means a disease of the brain. It takes a long time for the cow to show symptoms of the disease, but by the time the cow starts staggering around and acting strangely, the brain is a mess and the poor animal is nearly dead. That strange behavior is what gives the diseases its common name of "mad cow disease."

What is one example of the author keeping a lively tone even while discussing a disease?

The author uses technical language when defining the name "bovine spongiform encephalopathy."
The author explains how "[i]t takes a long time for the cow to show symptoms" after it is infected by the disease.
The author connects prions to humans by saying it is "very similar to other proteins in the brain."
The author humanizes the prion with playful language by saying "[i]f it manages to burrow into a corner."