Assertion: sponge's surface | /r/HasProperty | smooth
Facets:
Source sentences:
text: It has a smooth surface, covered with many scattered oscula.
text: In addition, the surface of a sponge may be smooth, velvety, rough with protruding skeletal elements called spicules, or conulose (i.e., provided with conical protrusions called conuli).
text: The surface around the many holes is smooth and glassy, although when handled, it crumbles like a slice of dried bread, thus the name.