{HEAD ~ The flow surface} includes a first portion and {TAIL ~ a second portion} extending downstream from the first portion 
includes
{ HEAD ~ The flow surface } includes a first portion and { TAIL ~ a second portion } extending downstream from the first portion
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH