Due to {HEAD ~ this increase} in the gap 70, the velocity of {TAIL ~ the air} that travels through the region 70 decreases as it travels through the gap 70 
Due to { HEAD ~ this increase } in the gap 70 , the velocity of { TAIL ~ the air } that travels through the region 70 decreases as it travels through the gap 70
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH