Assertion: sand dollar's tube foot | /r/ObjectUse | used in gas exchange
Facets:
Source sentences:
text: These pores are perforations in the endoskeleton through which the tube feet, used in gas exchange, project from the body.
text: These pores are perforations in the endoskeleton through which the tube feet, used in gas exchange, project from the body.
text: These pores are perforations in the endoskeleton through which the tube feet, used in gas exchange, project from the body.