Answer:
2. a thermal insulator
Explanation:
To save on heating bills, the roof of a building should be lined with a thermal insulator.
A thermal insulator will help prevent the house from loosing the heat trapped within the house.
- An insulator is a substance or device that does not allow for the conduction of heat and electricity.
- In this problem, an insulator does not allow for heat conduction.
- A conductor will allow heat pass through readily.
- So, to trap heat within the house, an insulator is best used.
