|aOxford bookworms library. Fantasy & horror. Stage 5.
|aStage 5: 1800 headwords.
|aWord count: 22,500.
|aA human being is a soft, weak creature. It needs constant supplies of air, water, and food ; it has to spend a third of its life asleep, and it can't work if the temperature is too hot or too cold. But a robot is made of strong metal. It uses electrical energy directly, never sleeps, and can work in any temperature. It is stronger, more efficient - and sometimes more human than human beings.