Assertion: raven | /r/ObjectUse | used as unofficial spotters
Facets:
value: for planes
type: PURPOSE
value: for enemy bombs
type: PURPOSE
Source sentences:
text: The first reference to an early version of the legend that Britain will fall if the ravens leave the Tower comes from July 1944, when ravens were used as unofficial spotters for enemy bombs and planes during the Blitz of World War II.