Further, a visual display device is provided in order that {HEAD ~ a swimmer} can recognize {TAIL ~ a starting signal} visually 
Further , a visual display device is provided in order that { HEAD ~ a swimmer } can recognize { TAIL ~ a starting signal } visually
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH