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

Q: Passage: Power plants are where electric power originates. They have electric generators that generate electric current through electromagnetic induction. Answer: power plants

A: Where does electric power originate?
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Q: Passage: If water is so simple, why is it special? Water is one of the few substances that exists on Earth in all three states of matter. Water occurs as a gas, a liquid and a solid. You drink liquid water and use it to shower. You breathe gaseous water vapor in the air. You may go ice skating on a pond covered with solid water ice in the winter. Answer: three matter states

A: In how many states does water exist on earth?
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Q: Passage: Figure 4.17 The chloroplast has an outer membrane, an inner membrane, and membrane structures called thylakoids that are stacked into grana. The space inside the thylakoid membranes is called the thylakoid space. The light harvesting reactions take place in the thylakoid membranes, and the synthesis of sugar takes place in the fluid inside the inner membrane, which is called the stroma. Chloroplasts also have their own genome, which is contained on a single circular chromosome. Answer: sugar

A:
Within the chloroplast, synthesis of what takes place in the fluid inside the inner membrane called the stroma?
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