Assertion: echinoderm's spine | /r/HasProperty | 1 cm thick
Facets:
Source sentences:
text: The slate-pencil urchin (Heterocentrotus mammillatus) of the Indo-Pacific has 12-cm spines that may be 1 cm thick—stout enough to be used for writing.
text: The slate-pencil urchin (Heterocentrotus mammillatus) of the Indo-Pacific has 12-cm spines that may be 1 cm thick—stout enough to…