Detailed Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Problem:Passage: All mammals have lungs that are the main organs for breathing. Lung capacity has evolved to support the animal's activities. During inhalation, the lungs expand with air, and oxygen diffuses across the lung's surface and enters the bloodstream. During exhalation, the lungs expel air and lung volume decreases. In the next few sections, the process of human breathing will be explained. Answer: lungs
Solution:
What are the main organs for breathing in a mammal?