A number of brain structures are listed below. If an area is primarily gray matter, write a in the answer blank; if mostly white matter, respond with b.  ____ (1) cerebral cortex ____ (2) corpus...

A number of brain structures are listed below. If an area is primarily gray matter, write a in the answer blank; if mostly white matter, respond with b.

 ____ (1) cerebral cortex

____ (2) corpus callosum and corona radiata

____ (3) red nucleus

____ (4) medial and lateral nuclear groups

____ (5) medial lemniscus

 ____ (6) cranial nerve nuclei

____ (7) spinothalamic tract

____ (8) fornix

 ____ (9) cingulate and precentral gyri