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

Ex Input:
Passage: Distillation is an effective method to separate mixtures comprised of two or more pure liquids. Distillation is a purification process where the components of a liquid mixture are vaporized and then condensed and isolated. In simple distillation, a mixture is heated and the most volatile component vaporizes at the lowest temperature. The vapor passes through a cooled tube (a condenser), where it condenses back into its liquid state. The condensate that is collected is called distillate. Answer: distillation

Ex Output:
What is a purification process where the components of a liquid mixture are vaporized and then condensed and isolated?

Ex Input:
Passage: An addition reaction is a reaction in which an atom or molecule is added to an unsaturated molecule, making a single product . An addition reaction can be thought of as adding a molecule across the double or triple bond of an alkene or alkyne. Addition reactions are useful ways to introduce a new functional group into an organic molecule. Answer: an addition reaction

Ex Output:
What is a reaction in which an atom or molecule is added to an unsaturated molecule, making a single product?

Ex Input:
Passage: Grazers, such as sea urchins, are organisms that feed on available plants. Sea urchins are omnivorous, eating both plant and animals. The sea urchin mainly feeds on algae on the coral and rocks, along with decomposing matter such as dead fish, mussels, sponges, and barnacles. Answer: grazers

Ex Output:
What are organisms that feed on available plants called?