Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
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Question: Rubber is an example of a(n) insulators that does not allow electrons to move through them.

Answer: Rubber is an example of what type of substances that do not allow electrons to move through them?


Question: People stopped adding lead to gasoline because of environmental pollution.

Answer: Why did people stop adding lead to gasoline?


Question: Sideways impact or bending are the primary causes of bone fractures.

Answer:
What are the primary causes of bone fractures?