Assertion: porpoise | /r/HasProperty | marine mammals
Facets:
Source sentences:
text: Porpoises are marine mammals and are part of the cetacean species which also includes dolphins and whales.
text: Because dolphins and porpoises are marine mammals they both breathe air, are warm-blooded, give birth and nurse their young with milk.
text: Both dolphin and porpoise are marine mammals categorized under order Cetacea.