"The energy sources must be shut down"; for a pneumatic valve, what would this mear Closed Open Neutral Passing Flag Reset

## Step 1<br />The problem is asking us to interpret the phrase "The energy sources must be shut down" in the context of a pneumatic valve. Pneumatic valves are devices that control the flow of compressed air in a pneumatic system.<br /><br />## Step 2<br />The phrase "The energy sources must be shut down" implies that the energy sources, which could be compressed air in a pneumatic system, must be stopped or turned off. This means that the pneumatic valve should be in a state where it does not allow any flow of compressed air.<br /><br />## Step 3<br />In the context of a pneumatic valve, this state is referred to as the "closed" position. In this position, the valve prevents the flow of compressed air, effectively shutting down the energy source.