Before exposure to appropriate light, {HEAD ~ the adhesive} retains {TAIL ~ its liquid or viscous character}, so that the optical conductor end 20 can be passed through the adhesive without any problems during the fitting process, in the process wetting the optical conductor end 
retains
Before exposure to appropriate light , { HEAD ~ the adhesive } retains { TAIL ~ its liquid or viscous character } , so that the optical conductor end 20 can be passed through the adhesive without any problems during the fitting process , in the process wetting the optical conductor end
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL 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