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

Input: Consider Input: Passage: An ideal gas is one that follows the gas laws at all conditions of temperature and pressure. To do so, the gas would need to completely abide by the kinetic-molecular theory. The gas particles would need to occupy zero volume and they would need to exhibit no attractive forces what so ever toward each other. Since neither of those conditions can be true, there is no such thing as an ideal gas. A real gas is a gas that does not behave according to the assumptions of the kinetic-molecular theory. Fortunately, at the conditions of temperature and pressure that are normally encountered in a laboratory, real gases tend to behave very much like ideal gases. Answer: ideal gas

Output: What is the term for a gas that completely abides by the kinetic-molecular theory?

Input: Consider Input: Passage: A snowflake is made of ice, or water in the solid state. A solid is one of four well-known states of matter. The other three states are liquid, gas, and plasma. Compared with these other states of matter, solids have particles that are much more tightly packed together. The particles are held rigidly in place by all the other particles around them so they can't slip past one another or move apart. This gives solids a fixed shape and a fixed volume. Answer: plasma

Output: What state of matter completes the list: solid, liquid, gas?

Input: Consider Input: Passage: Plants are multicellular eukaryotes that are placed in the Plant Kingdom . Plant cells have cell walls that are made of cellulose. Plant cells also have chloroplasts. They allow plants to make food by photosynthesis. In addition, plants have specialized reproductive organs that produce gametes. Male reproductive organs produce sperm. Female reproductive organs produce eggs. Male and female reproductive organs may be on the same plant or on different plants. Answer: cellulose
Output: Plant cells have cell walls that are made of what?