Or, {HEAD ~ the substrate} may further include {TAIL ~ an absorber} for absorbing the surface acoustic wave propagated in the surface acoustic wave propagation region 
include
Or , { HEAD ~ the substrate } may further include { TAIL ~ an absorber } for absorbing the surface acoustic wave propagated in the surface acoustic wave propagation region
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH