{TAIL ~ The fiber aggregates} are useful, for example, for flowback control in wellbores and {HEAD ~ reservoirs} 
{ TAIL ~ The fiber aggregates } are useful , for example , for flowback control in wellbores and { HEAD ~ reservoirs }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD