Assertion: fuel cell's fuel | /r/MadeOf | exposure
Facets:
value: to high heat
type: CAUSE
value: to pressure
type: CAUSE
Source sentences:
text: Fossil fuels are hydrocarbons, primarily coal and petroleum (liquid petroleum or natural gas), formed from the fossilized remains of ancient plants and animals by exposure to high heat and pressure in the absence of oxygen in the Earth's crust over hundreds of millions of years.