Fact 1: Agreenhouse is used to protect plants by keeping them warm.

Fact 2: Temperatures go from warm to hot.

Given the two facts above, answer the question "What is used to protect plants by keeping their temperature?" with the following options: 
- a white house
 - energy
 - an electric stove
 - a microwave
 - electricity
 - a thermometer
 - exoskeleton
 - a greenhouse


 

        a greenhouse 