TOEFL Listening: ETS-TOEFL听力机经 - N6NPKQ0NM6AKO1B5P$

What trait allows adult ground squirrels to confront rattlesnakes? A. They can determine whether a snake is dangerous by its rattle. B. They have the ability to make themselves larger. C. They have an immunity to rattlesnake venom. D. They can move more quickly than rattlesnakes.