Assertion: sea urchin | /r/HasAspect | five pairs of external gills
Facets:
Source sentences:
text: Most sea urchins possess five pairs of external gills attached to the peristomial membrane around their mouths.
text: Most sea urchins possess five pairs of external gills attached to the peristomial membrane around their mouths.
text: Most sea urchins possess five pairs of external gills, located around their mouths.