{TAIL ~ The flexible sheets} are attached to {HEAD ~ structural members}, that is, to purlins beneath the roof panels 
{ TAIL ~ The flexible sheets } are attached to { HEAD ~ structural members } , that is , to purlins beneath the roof panels
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH