Given the task definition and input, reply with output. Given a scientific passage and an answer, generate a question for the given answer.

Passage: Materials that have high resistance to electric current are called electric insulators . Examples include most nonmetallic solids, such as wood, rubber, and plastic. Their atoms hold onto their electrons tightly, so electric current cannot flow freely through them. Dry air is also an electric insulator. You can learn more about electric insulatorsas well as how to test whether a material is an insulatorby doing the activity at this URL:. Answer: electric insulators
What do you call materials that have high resistance to electric current?