Assertion: kelp's pneumatocyst | /r/CapableOf | help keep frond
Facets:
Source sentences:
text: Many species of kelp have pneumatocysts, which are gas-filled bladders that help keep the fronds afloat in the water.
text: species of kelp have pneumatocysts, which are gas-filled bladders that help keep the fronds afloat in the water.