instruction:
Given a scientific passage and an answer, generate a question for the given answer.
question:
Passage: Figure 29.17 The tails of the Hale-Bopp comet point away from the Sun, evidence that light has momentum. Dust emanating from the body of the comet forms this tail. Particles of dust are pushed away from the Sun by light reflecting from them. The blue ionized gas tail is also produced by photons interacting with atoms in the comet material. (credit: Geoff Chester, U. Navy, via Wikimedia Commons). Answer: momentum
answer:
The tails of the hale-bopp comet point away from the sun, evidence that light has what property of motion?

question:
Passage: Solutions can also become supersaturated , where the amount of solute dissolved exceeds its solubility. Supersaturation most commonly occurs when a saturated solution is slowly cooled. They occur frequently in geological and meteorological processes. Supersaturated systems are unstable, and eventually, the solute will precipitate until a saturated solution is regenerated. We can quantify supersaturation by looking at solubility curves. If the ratio of solute to solvent is above the saturation curve at the given temperature, the solution is supersaturated. If it is on the curve, the solution is saturated, and if it is below the curve, the solution is unsaturated. Answer: its solubility
answer:
Solutions can also become supersaturated , where the amount of solute dissolved exceeds what?

question:
Passage: When gas pressure-forces are used to move an object then work is done on the object by the expanding gas. Work can be done on the gas in order to compress it. Answer: expanding gas
answer:
When gas pressure-forces are used to move an object the work is done on the object by?