Whether trying to live with the depressing spectacle of drought or battling rampaging floods or suffering with a debilitating disease caused by contaminated drinking supplies, people in almost every corner of the world have had their problems with the vagaries of water. Although water covers much of our planet, more than 97 % is in the oceans. Another 2 % is unusable ice. More over, much of the remainder is polluted. So much for the supposed abundance ! Developed and developing countries alike are now talking about a crisis.What of the future Will water needs reach a peak Unhappily, LIN experts expect demands to double in the next 25 years. (61)This will coincide with increasing population and industrialization and the attendant risk of factory and human waste further contaminating rivers, lakes and ground water. So, is there any hope of a solution The answer, fortunately, is that the problem is being tackled.(62) Specialists in many countries are developing methods to improve supply and conservation and protect quality, and a number of ambitious programs have been undertaken. Good fore casting- including predictions of snow, rain, river levels and soil loss --can help scientists head off, or at least cope with floods. Canals can ease one of the major water-related problems: drought. With something like three quarters of the world’ s fresh water tied up as ice, plans to drag ice bergs to drought areas have been around for a long time; attempts to overcome the drawbacks are still being made. A great deal of energy would be needed to the ice and pump the water inland, and the ice might melt before reaching its destination. In addition, research into desalting seawater continues with new and improving desalting methods although no method can yet promise truly low-cost fresh water. Fossil water --underground water dating back to the ice age could be drilled for in’ some areas but supplies are non-renewable. Work continues in all these areas. It is obvious that a lot of time, money and research is going into finding solutions to some of the problems.(63) However, worldwide, the ugly fact remains that something like 250 million new cases of waterborne diseases are discovered every year and 25,000 people die from them every day. Pollution continues to plague all of us. "Even as the rain falls", says Russell W. Peterson, former chair man of the US Council on Environmental Quality," it scours pollutants from the air. In fact, nearly all the pollutants the people of the world discharge into the air end up in our water systems." (64) Therefore, whether tainted by industrial waste, sewage or other pollution, unreliable water supplies frequently create breeding grounds for deadly water-borne diseases when safeguards and purification are inadequate. Millions of people, therefore, continue to be affected by water-related problems and contrary to popular belief, future water supplies are not inexhaustible. So the situation is very serious, especially in view of the UN estimates of demand. (65) Although projects to provide ever increasing supplies of water indicate that a growing number of countries are aware of the present problems and of those to come, these more often than not are highly expensive and not very practical, and very time-consuming when time is commodity in short supply. Therefore, while research in these areas is important, the eventual solution would definitely appear to be worldwide conservation and pollution control--in other words, a greater respect for our most valuable natural resource. This will coincide with increasing population and industrialization and the attendant risk of factory and human waste further contaminating rivers, lakes and ground water.
Petroleum is a very important mineral. It gives us heat and light. It also gives us power for our cars, planes, and ships. It gives us power for machines of all kinds.How was petroleum created Scientists believe petroleum was formed from the remains of plants and animals. These plants and animals lived and died millions of years ago. Remains are what is left after a plant or animal has died.What exactly is petroleum Petroleum is a mineral that is a mixture of hydrocarbons. It is an oily liquid which may be brown, green, or black in colour. The word "petroleum" comes form Latin and Greek. It means "rock oil".Crude oil is petroleum that comes directly from deep in the ground. It is then taken to a refinery. A refinery is a kind of factory with equipment in it to refine oil. At a refinery the crude oil is purified and separated into its various parts. From the refined petroleum we obtain important products, such as gasoline, kerosene, fertilisers, detergents, plastics, drugs, and perfumes. These are just a few of the thousands of useful products we get from this valuable mineral-petroleum. It gives us power for().
All mammals, except man and the monkey, swim naturally from birth. For man, like the monkey, it is not instinctive to float. Deaths by drowning are common everywhere. In the United States alone, about 7,000 children under four drown each year.Everything possible is done to prevent such tragedies. One solution is particularly effective teaching children to swim while they are still babies. Most large towns in Florida and California already run lessons for babies and infants. The idea has spread to Europe where, in several countries, special courses are now arranged for children from seven to twenty-four months.The first step is to eradicate the child’ s fear of the water. Next, he is taught to float. Once he can do this naturally and without fear, the teacher can move on the breathing, and arm and leg movements. Before long, the child grasps the technique and can propel himself through the water. Where are swimming courses arranged for children