chemical process in which one atom or ion or group changes places with another
a mutual expression of views (especially an unpleasant one)
the act of giving something in return for something received
the act of changing one thing for another thing
a workplace that serves as a telecommunications facility where lines from telephones can be connected together to permit communication
change over, change around, as to a new order or sequence
a reserve of money set aside for some purpose
a supply of something available for future use
