When we turn on a tap to get water, or press a switch to get electricity, we do not think of all the pipes and wires which bring these main services to our homes. The water is brought from the waterworks to each street by a large underground pipe—a water main. The water in this pipe is then forced by pressure into the smaller pipes which carry it to storage tanks at the tops of the buildings. Other pipes bring the water down from the storage tank to the kitchens and bathrooms in the building. When the water has been used, it is taken away from the building by drainpipe. These take the waste water to another large pipe under the road—the main sewer. The waste water then flows along the sewer to the sewage works where it is cleaned. This 'clean' water is then poured into the sea or into a river, or in some countries, sent back to the waterworks to be used again. Electricity is also brought to the house by a main, in this case a cable. This cable may be underground or, in country districts, it may hang above ground on pylons. The cable is connected to a meter in the building. This meter measures the amount of electricity that is used in the building. Near the meter there is a master switch which can cut off the supply of electricity. There are also fuse boxes between the master switch and the wires which take the electricity to each of the switches in the building. All these wires, fuses and switches are the 'wiring circuit'. It can be inferred from this passage that______.