The opening of the exhaust system may also have {HEAD ~ a tubing} to allow {TAIL ~ the exhaled air} to be moved even further away 
to allow
The opening of the exhaust system may also have { HEAD ~ a tubing } to allow { TAIL ~ the exhaled air } to be moved even further away
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH