(September 2014). A general sales agent (GSA) is a sales representative for an airline in a specific country or region. Typically, the GSA is responsible for selling all products of the airline in its region which includes flight tickets and cargo space. A GSA will typically sell the product of more than one airline.
Definition of standing wave. : a single-frequency mode of vibration of a body or physical system in which the amplitude varies from place to place, is constantly zero at fixed points, and has maxima at other points.
1 If two waves with the same amplitude and wavelength travel in opposite directions they alternate between constructive and destructive interference. The resultant looks like a wave standing in place and, thus, is called a standing wave.  Nodes are points of no motion in standing waves.