ramp {Ans: the ground area outside of the airport terminal where airplanes park}leg {Ans: flight segment between stops}pressurization {Ans: a mechanical process that keeps the atmospheric conditions on board as near the density on the ground as possible.}PSU {Ans: Passenger Service Unit}Out and Back {Ans: Assignment in which crewmembers departs from and returns to their base in same day}portable water {Ans: water that has been purified and certified by local authorities as safe for drinking}