Assertion: bronchus's cartilage | /r/CapableOf | serve the purpose
Facets:
value: because of its rigidity
type: CAUSE
value: often
type: TEMPORAL
Source sentences:
text: Because of its rigidity, cartilage often serves the purpose of holding tubes open in the body.
text: Because of its rigidity, cartilage often serves the purpose of holding tubes open in the body.