Given a statement and question, generate the answer to the question such that the answer is contained in the statement.

[Q]: statement: An animal with an additional joint in its mandible became more mammal-like as it continued to evolve, question: What did an animal with a joint in its mandible become?
[A]: mammal

[Q]: statement: fish secrete a mucous covering over their exterior to help protect from predators and parasites and reduce friction with the liquid substance they live in., question: What do fish secrete over their exterior to help protect against predators and parasites?
[A]: mucous

[Q]: statement: An effective treatment against bacteria has no effect on viruses, question: What does an effective treatment against bacteria have no effect on?
[A]:
viruses