I just took a test in school today. What question was I asked?

Question I was asked: A scientist plans to investigate the nervous system of sea slugs. What should the scientist do first?

I just took a test in school today. What question was I asked?

Question I was asked: Jake's cats eat food from a can. The cats come running into the kitchen when they hear the electric can opener. Now, each time Jake's mother opens a can of corn, the cats come running. This is an example of

I just took a test in school today. What question was I asked?

Question I was asked:
Base your answer on the information below and on your knowledge of science. A baseball strikes the roof of a car and dents it. The paint on the roof begins to crack and chip, exposing the metal. The exposed metal on the roof rusts, eventually causing a small hole in the roof. Which event is a chemical change?