Assertion: blue whale | /r/HasProperty | swift
Facets:
Source sentences:
text: The blue whale was too swift and powerful for the 19th century whalers to hunt, but with the arrival of harpoon cannons, they became a much sought after species for their large amounts of blubber.
text: The blue whale was too swift and powerful for the 19th century whales to hunt but because invention of harpoon cannons, it become easier to catch blue whales.