If you live in a city of North America or Europe, you have probably never thought much about water. Whenever you need some, you turn on the tap and there it is. Millions of people in other parts of the world are not so lucky. They have trouble getting enough water for their basic needs. This situation may soon become common all around the world, scientists believe. In fact, they say that the lack of clean water may be one of the biggest issues in the twenty- first century.
The reasons for this are clear. On the one hand, people are using more water than ever. Over the last fifty years, the population of the world has more than doubled. So has the demand for water ľ for home use, for farming and for industry. On the other hand, supplies of clean water are disappearing. Many sources of surface water ľ such as rivers, lakes and streams ľ are too polluted and unhealthy foe use as drinking water. This has forced more and more people ti drill wells so they can get water from underground.
There are enormous amounts of water deep underground in lakes called aquifers. Until recently, scientists believed this ground water was safe from pollution. Then, in the 1980s, people in the USA began to find chemicals in their well water, and scientists took a closer look at what was happening. Weldon Spring, Missouri, for example, was the site of a bomb factory during World War II. The factory was destroyed after the war, but poisonous chemicals remained on the ground. Very slowly, these chemicals dripped down through the ground and into the aquifer. It took thirty- five years for the chemicals from Weldon Spring to reach the aquifer. Once they did, however, the water from that aquifer was no longer drinkable. It probably never will be drinkable again. Groundwater is not renewed regularly by the rain, like rain or river water. Thus, if a harmful chemical gets into an aquifer, it will stay there for a very long time. Furthermore, it is nearly impossible to remove all the water in an aquifer and clean out the pollutants.
Industrial sites like Weldon Spring are one cause of underground pollution. There thousands of such cites in the USA alone, and many others around the world. Groundwater pollution is also caused by modern farming methods, which require the use of large amounts of chemicals in the fields. And finally, yet another important cause of groundwater pollution is waste. That includes solid waste (garbage) thrown away in dumps and landfills, and also untreated human and animal waste.
The situation is indeed very serious. Fortunately, there are many aquifers and they are very large. Only a small number have been seriously damaged so far. But if the world doesnĺt want to go thirsty in the near future, further pollution must be prevented. Around the world, governments must make real changes in industry, agriculture and waste disposal.
Answer the questions:
1. Are all people in the world lucky to have enough water?
2. Why did the demand for water increase in the recent fifty years?
3. Are supplies of clean water unlimited?
4. Why do people drill wells?
5. Where is water safe from pollution?
6. What happened to the aquifer in Weldon Spring?
7. Is groundwater regularly renewed?
8. Are there many cites in the world similar to Weldon Spring?
9. What are the other reasons for polluting aquifers?
10. Why do governments have to make real changes in industry, agriculture and waste disposal?
Read the text.
The abundance of water in liquid, solid and gaseous state is a matşter of common observation. Water is not only the most abundant comşpound, but it is also very important for life. To be sure life would be impossible without water. For many purposes water must be pure. The purest natural water is rain. But we can't say that it is really pure. The same can be said about ground water. It contains a great deal of impuşrities which fail to settle. Dissolved substances do not settle and don't evaporate with water, and this makes their removal difficult. One of the most important problems is to obtain water sufficiently pure to meet our needs. The choice what process is to be used for purification of water depends upon the uses for which it is intended as well as the imşpurities it contains. Water used for steam boilers should be free from substances that cause corrosion and scale formation. Water for washing should not contain substances that react with soap. When water is to be used for drinking, it is necessary to kill the microbes it may conştain. To achieve this, water which is to be purified is thoroughly filştered. Another way to purify water is to boil it. None of these methods is fit for producing pure water in the chemical sense, because most of the soluble salts are unaffected by the treatment. To remove these and to prepare chemically pure water suitable for scientific use, we take advantage of the fact that water is usually changed to steam while most of the dissolved substances as have already been mentioned are not volatile. If we condense the steam, we are thus able to remove all the impurities except volatile ones. This process is called distillation. Disştilled water has many uses, both in the laboratory and in industry, when even small quantities of impurities are undesirable.
Entitle the text, then divide it into logical parts thus making a plan. Retell the text.
Read the text:
The relations between science and society have changed over the centuries. When modern science was born during the Renaissance, its first epoch was a fight for its life against an authoritarian and represenştative society. After the fight had been won, science released creative forces leading to the scientific avalanche. The second epoch started in the Age of Enlightment, in itself partly the result of the application of scientific thinking to society. It resulted in the destruction of the feudal society and added more momentum to the march of science. The third epoch began with the technological application of science, which has done more to change the quality of human life than any other develşopment in the history of mankind.
Thus far science had displayed only a benevolent aspect. But the forth epoch is marked by increasing fear of the negative aspects of scişence which are the product of its very success. The dynamic society caused by science is marked by a large number of exponentially inşcreasing variables. Too many of them are now approaching catastrophic values. The atomic bomb, the population explosion, and the deterioraştion of the human environment are all the products of science, or rather of the malfunctioning of the relations between science and socişety. We are facing a serious crisis. There are many people, including scientists, who call these fears "doomsday prophesies", and claim the dangers are exaggerated. Are not the bombs in the hands of responsişble people? Does not the Earth abound in waste land ready to absorb the population increase? Is pollution really such a serious problem? Admittedly some of the fears may be exaggerated, but no one who has made any serious study of the arms race and the population explosion can fail to be alarmed. Lack of concern stems either from ignorance or from the attitude of apres nous le deluge (´ţ˝Űň ÝÓ˝ §ţ˛Ř ´ţ˛ţ´). Among scientists there also exists a third variant, often termed the "ivory tower" attitude: a scientist should be a scientist and nothing else. His works aim at the increase of knowledge, and knowledge is a good in itself. He should leave to others the task of deciding how to use it. This attitude worked perfectly throughout the whole long era during which science contributed almost exclusively to the progress of manşkind. But this is no longer the case. How are we to tackle this crisis? Some have adopted the defeatist view that our scientific-technological culture carries within itself the seeds of its own destruction. Man rules the Earth at present but will soon be extinct, like dinosaurs who were once masters of the world. Our crazed technology and outmoded poşlitical systems are the instruments of our own destruction. Perhaps a few of us can escape and start a new culture if we get away from the Blue Planet in time and form a space colony. All this may be true, but we must strive instead for other solutions. They don't lie easy to hand. Some think that the development of science and technology should be halted. This "technophobic" view is shortsighted. Science and techşnology confer such enormous benefits that they must not be halted, but used in a sensible way. We come closer to the truth if we say that it is the rules that govern world politics that must be changed: power polşitics have now become so dangerous that they must be abolished. Scişentists and technologists are accustomed to look with pride at all the "progress curves" that rise exponentially and think it is their agreeable duty to keep them rising or even induce them to rise still faster. But we have now learned that the rise of many of these curves spells disaster, and scientists cannot plead innocence by putting the blame on others by saying: "We, scientists, are simply doing our job, and "others" must take the blame if our findings are used irresponsibly." There are no "others" willing to assume the responsibility. There are many instances in which new discoveries can bring power and wealth to certain groups, but only at the expense of others. Possibly mankind as a whole is payşing the price through a decline in security, the deterioration of human environment, and the widening gap between the rich and the poor. In cases such as these, who is there to advocate the interests of mankind? Indeed, there are few who are capable of it, since often only a handful of specialists really understand the consequences of new discoveries.
Answer the questions:
1. What to your mind might be a title of the text?
2. How have the relations between science and society changed?
3. What scientific achievements are gaining catastrophic values?
4. Are the dangers really exaggerated?
5. What is the "ivory tower" attitude to scientific achievements?
6. In what case can we escape our own destruction on this planet?
7. What is a "technophobic" point of view on the development of scişence?
8. Who is there to advocate the interests of mankind?
9. What else besides science needs reforming?
10.What attitude to science and its development is called out-of-date?