In {TAIL ~ the alternative} to assembly 22, {HEAD ~ a specular surface} may be formed by vapor deposition of aluminum directly onto the surface 21 of the support 20 
In { TAIL ~ the alternative } to assembly 22 , { HEAD ~ a specular surface } may be formed by vapor deposition of aluminum directly onto the surface 21 of the support 20
REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH