Fact 1: Coal is used for generating heat by burning.

Fact 2: Fossil fuels are coal, oil and natural gases.

Given the two facts above, answer the question "What is used for generating heat by burning?" with the following options: 
- carbon dioxide
 - sunlight
 - calcite
 - Calcium carbonate
 - water
 - ice
 - peachleaf willow
 - fossil fuels


 

        fossil fuels 