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

Q: Passage: An ionic bond is the force of attraction that holds together oppositely charged ions. Ionic bonds form crystals instead of molecules. Table salt contains ionic bonds. Answer: ionic bond

A: What term means the force of attraction that holds together oppositely charged ions?
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Q: Passage: Runoff is likely to cause more erosion if the land is bare. Plants help hold the soil in place. The runoff water in Figure below is brown because it eroded soil from a bare, sloping field. Can you find evidence of erosion by runoff where you live? What should you look for?. Answer: erosion

A: Runoff is likely to cause more what if the land is bare?
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Q: Passage: Many ecosystems have changed because of human actions. The human species is responsible for a range of environmental problems. Answer: to transport

A:
What is the main function of the cardiovascular system?
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