Given a scientific passage and an answer, generate a question for the given answer.
Q: Passage: All materials have some resistance, but certain materials resist the flow of electric current more or less than other materials do. Materials such as plastics have high resistance to electric current. They are called electric insulators. Materials such as metals have low resistance to electric current. They are called electric conductors. Answer: electric conductors
A:
Materials such as metals have low resistance to electric current, what are they called?