Assertion: river | /r/ObjectUse | used for navigation
Facets:
value: for thousands of years
type: TEMPORAL
value: since roman times
type: TEMPORAL
Source sentences:
text: Rivers have been used for navigation for thousands of years.
text: The river has been used for navigation since Roman times, and is still navigable by small boats as far as Bodiam Castle.
text: Rivers have been used for navigation for thousands of years.