The choice of {TAIL ~ material} will depend on a variety of factors such as the physical and chemical properties of {HEAD ~ the material} being employed 
The choice of { TAIL ~ material } will depend on a variety of factors such as the physical and chemical properties of { HEAD ~ the material } being employed
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH