Answer:
on some vehicles you can remove the gas cap and have someone listen for the fuel pump to "buzz"; for vehicles where you cannot do this you could remove the main fuel line under the hood and turn the key to the "on" position and see if fuel squirts out, but be careful some fuel lines are pressurized, if you're not sure you could ask the attendant at your local auto parts store, usually these guys have been working on cars a long time