Assertion: solar energy | /r/ObjectUse | used by people
Facets:
value: for hundreds of years
type: TEMPORAL
value: since ancient times
type: TEMPORAL
value: to cook food
type: PURPOSE
value: by using simple magnifying glasses
type: MANNER
Source sentences:
text: Solar energy has been used by people since ancient times by using simple magnifying glasses to concentrate the light of the sun into beams so hot they would cause wood to catch fire.
text: This means solar energy has been used by people for hundreds of years to cook food, keep warm, and to dry clothes.