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

Input: Consider Input: Passage: The Sun gives off energy in tiny packets called photons . Photons travel in waves. Figure below models a wave of light. Notice the wavelength in the figure. Waves with shorter wavelengths have more energy. Answer: photons

Output: What are the tiny packets of energy the sun gives off called?

Input: Consider Input: Passage: and procaine. Not only do catalysts greatly increase the rates of reactions, but in some cases such as in petroleum refining, they also control which products are formed. The acceleration of a reaction by a catalyst is called catalysis. Answer: reactions

Output: Catalysts can greatly increase the rates of chemical what?

Input: Consider Input: Passage: The theory of plate tectonics explains most of the features of Earth's surface. Plate tectonics helps us to understand where and why mountains form. Using the theory, we know where new ocean floor will be created and where it will be destroyed. We know why earthquakes and volcanic eruptions happen where they do. We even can search for mineral resources using information about past plate motions. Plate tectonics is the key that unlocks many of the mysteries of our amazing planet. Answer: plate tectonics
Output: What theory explains most of the features of earth's surface?