Assertion: aid climbing | /r/CapableOf | become popular
Facets:
value: during the period
type: TEMPORAL
Source sentences:
text: Aid climbing, climbing using equipment that acts as artificial handhold or footholds, became popular during the period 1920–1960, leading to ascents in the Alps and in Yosemite Valley that were considered impossible without such means.
text: Aid climbing, climbing using equipment that acts as artificial handhold or footholds, became popular during the period 1920–1960, leading to ascents in the Alps and in Yosemite Valley that were considered impossible without such means.