Assertion: natural gas's use | /r/HasProperty | limited in ancient times
Facets:
value: due to lack of knowledge and technology
type: CAUSE
Source sentences:
text: In ancient times, the use of fossil fuels may have been limited due to lack of knowledge and technology, but civilizations tried and, to some extent, managed to make the most of the fossil fuel resources they could extract and use in their everyday lives.
text: In ancient times, the use of fossil fuels may have been limited due to lack of knowledge and technology, but civilizations tried and, to some extent, managed to make the most of the fossil fuel resources they could extract and use in their everyday lives.