Assertion: penguin's feather | /r/CapableOf | keep the body
Facets:
Source sentences:
text: The black feathers on the back are thought to absorb heat from sunlight and keep the body warm.
text: Short, glossy feathers cover its body to form a dense, furlike covering, which is waterproof and helps keep the bird warm.
text: Birds are unique as the only animal's which have feathers covering their body.
text: These include the main quill-like feathers called contour feathers that cover their bodies, as well as two types of insulative feathers: plumules (downy feathers attached directly to the skin) and afterfeathers (downy plumes attached to the main feathers).