{HEAD ~ A protector} adapted to accommodate {TAIL ~ a transparency} inserted therein in a moist state, the transparency drying out while in the protector and being thereafter maintained in clean, dust free and dry condition so that it is useable with an overhead optical projector which casts the image carried by the transparency onto a viewing screen 
{ HEAD ~ A protector } adapted to accommodate { TAIL ~ a transparency } inserted therein in a moist state , the transparency drying out while in the protector and being thereafter maintained in clean , dust free and dry condition so that it is useable with an overhead optical projector which casts the image carried by the transparency onto a viewing screen
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH