I.S.題-electricity(急!急!) 2

這份I.S.功課後日要交了,希望各位幫我解答呢的題目,THX!! ^_^

Household electricity:

3.The earth socket carries the "______________" current from the metal case of the appliance to the ground.
It provides another ________ for the electric current to flow.The electric current will not flow through our __________.The fuse in the plug will _________ and __________ the circuit.Earth wire protects us against any electric shock.