Instructions: You need to read the given passage and construct a question about the information present in the passage. The question should be answerable from the passage. Most importantly, only those questions are allowed whose answers cannot be determined from a single sentence. Do not generate questions that require only a single sentence to answer. Instead, try to combine two sentences and create a question from that combination. Do not create open-ended questions, i.e., the answers to them cannot be found precisely from the information provided in the passage.
Input: Paragraph- Sent 1: Electric current cannot go through empty space.
Sent 2: Electricity needs something to flow through.
Sent 3: Electricity cannot flow through all materials.
Sent 4: Some materials resist the flow of electricity.
Sent 5: Some materials let electricity pass through easily.
Sent 6: Scientists classify these into two groups.
Sent 7: These groups are called conductors and insulators.
Sent 8: Materials that allow electrons to flow freely are called electric conductors.
Sent 9: Electricity is able to race through these materials.
Sent 10: Copper, aluminum, and steel are good conductors.
Sent 11: Materials that resist the flow of electricity are called electric insulators.
Sent 12: Instead of racing, the current may travel in slow motion, if at all.
Sent 13: Wood, rubber, and plastic are examples of electric insulators.
Sent 14: You probably know that electric wires are made of metal.
Sent 15: They typically have a rubber or plastic coating.
Sent 16: Do you know why?
Sent 17: Metals are good electric conductors.
Sent 18: They offer little resistance to electricity.
Output:
What materials let electricity pass easily?