Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.

[EX Q]: Question: When a mountain stream flows onto flatter land and comes to a stop rapidly, what do the deposits form? Answer: alluvial fan
[EX A]: In arid regions, a mountain stream may flow onto flatter land. The stream comes to a stop rapidly. The deposits form an alluvial fan ( Figure below ).

[EX Q]: Question: What takes both the shape and the volume of their container? Answer: gases
[EX A]: Solids have a fixed volume and a fixed shape. Liquids have a fixed volume but take the shape of their container. Gases take both the volume and the shape of their container.

[EX Q]: Question: In which organs does gas exchange take place between blood and air? Answer: lungs
[EX A]:
Respiration begins with ventilation . This is the process of moving air in and out of the lungs. The lungs are the organs in which gas exchange takes place between blood and air.