Â© PMA of Georgia 2010. Venting. This concept of the plumbing system breathing (while. conceptually accurate) is somewhat confusing to a. craftsperson when trying to understand specifically what. the purpose of the vent system is.
Definition of traffic jam. : a situation in which a long line of vehicles on a road have stopped moving or are moving very slowly stuck in a traffic jam.
Colours in traffic lights. Red light. This communicates to drivers around a specific junction to stop. It helps to prevent collision of vehicles coming from other directions. Amber (yellow) light. It warns the driver approaching the junction to stop because the signal is about to change to red.