Assertion: arachnoid | /r/HasProperty | middle
Facets:
Source sentences:
text: The three membranes covering the spinal cord and brain: dura mater (external), arachnoid (middle), and pia mater (internal).
text: There are three layers: the dura mater (outer), arachnoid membrane (middle) and the pia mater (inner layer).
text: The three membranes covering the spinal cord and brain: dura mater (external), arachnoid (middle), and pia mater (internal).
text: The three membranes covering the spinal cord and brain: dura mater (external), arachnoid (middle), and pia mater (internal).