Assertion: frontal sinus | /r/CapableOf | appear at the age of six
Facets:
Source sentences:
text: The sphenoid sinus appears at the age of three, and the frontal sinuses first appear at the age of six, and fully develop during adulthood.
text: The sphenoid sinus appears at the age of three, and the frontal sinuses first appear at the age of six, and fully develop during adulthood.