Think about the idiomatic expression in the following excerpt from "The Notorious Jumping Frog of Calaveras County." “[Smiley’s
dog] would grab that other dog … and hang on till they throw up the sponge.…” What does the expression “thrown up the sponge” most likely indicate about the people watching the dog fight?
An idiom is a phrase that has a figurative, non-literal meaning. We can't conclude what this type of phrase means based on the meanings of individual words that make it up. Here, we have the idiom <em>throw up the sponge</em>. No one is literally throwing up sponges. This phrase means<em> </em><em>to give up a contest </em>or <em>to acknowledge defeat</em>.
Based on this information, we can conclude that the dogs are fighting until the people who own them admit that they lost the bet.