Текст В

Centralized water supply dates back to 2500 BC. Ancient Egypt had complex engineering structures for the purpose. Yet to this day the percentage of the population enjoying centralized water supply on the African continent, and in Asia, too, is very low.

In our country, at the time of the revolution of 1917, only one-third of the towns had running water laid on, and then, as a rule, only in the central part of the town. In the pre-war period of industrial development running water reached millions of flats all over the country. But many of the systems and practically all in the western and central parts of European Russia, were destroyed during the war and had to be built anew.

Fresh water shortage was first mentioned soon after the end of the Second World War. The first to feel the stint was Europe. The problem came to many as a complete surprise, something in the nature of an unexpected “catastrophe”. This catastrophe, however, should have been foreseen, for it follows logically from the development of human life on our planet and of Man’s industrial activity.

In the absence of centralized water supply, a man can do with about 25 litres of water a day for his various personal needs. But in the modern city water consumption per person is much higher. An average of 300 to 500 litres of water is spent daily on household and sanitary needs per one inhabitant of a modern city. You can see this vastly exceeds the necessary minimum of 25 litres. Why the difference? Not because people keep their taps open. Because water is so abundant that no one thinks twice about taking a shower, or a bath, using the washing machine, washing the cars, etc. The volume of water consumption is indicative not only of the efficiency of the water supply but also of the population’s living standards.

Find in the text the sentence in which it is explained why people consume much more water than they need.