- Coal is used for generating heat by burning
- To generate something means to produce something
- So, coal is used for producing heat by burning

- Burning wood is used to produce heat
- A tree contains wood
- Therefore, burning trees is used to produce heat

- Coal is used for producing heat by burning
- Burning trees is used to produce heat
- Therefore, coal and trees are both used for producing heat

Therefore, coal and trees are both used for producing heat
Question: Coal and trees are resources found in Maryland. Both resources are used for
Context: - Coal is used for generating heat by burning 
- To generate something means to produce something 
- Burning wood is used to produce heat 
- A tree contains wood