{TAIL ~ The routes} 4 to 9 are provided in an overhead space in {HEAD ~ a clean room} 
{ TAIL ~ The routes } 4 to 9 are provided in an overhead space in { HEAD ~ a clean room }
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD