Given a scientific passage and an answer, generate a question for the given answer.

Input: Consider Input: Passage: Pressure is the result of force acting on a given area. It can be represented by the equation:. Answer: pressure

Output: What property is the result of force acting on a given area?

Input: Consider Input: Passage: Immovable joints do not allow the bones to move at all. In these joints, the bones are fused together by very tough collagen. Examples of immovable joints include the joints between bones of the skull. You can see them in Figure below . Answer: immovable joints

Output: The joints that are between the bones that make up the skull are what kind of joints?

Input: Consider Input: Passage: Behind each release of gas is an army of gut bacteria undergoing some crazy biochemistry. These bacteria break down the remains of digested food through fermentation, creating gas in the process. Learn what these bacteria have in common with beer brewing at http://youtu. be/R1kxajH629A?list=PLzMhsCgGKd1hoofiKuifwy6qRXZs7NG6a . Answer: fermentation
Output: Bacteria break down the remains of digested food through a processed called what?