Then, the mask is fixed in {HEAD ~ a rolled up state}, thereby forming {TAIL ~ the roller} 40 
forming
Then , the mask is fixed in { HEAD ~ a rolled up state } , thereby forming { TAIL ~ the roller } 40
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH