positive sides of different heating systems. For example the positive side of electrical heating sytem is its convenience, but the negative is the need for electricity. The same is with solar heating where the initial investment is quite large, but in longer perspective it costs it self back, because money is spent only for maintenance what requires very littel resources. With this work I got the answers for my hypothesea. Fireplaces, stoves and cookers are indeed the most popular heating sytems in Estonia, mainly beacause their cheapness and simplicity. However collapsed the hypothesis, in which I claimed that in certain negative outdoor temperature the cost for heating will remain constant. Actually the cost for wood increased about 0,5 kg for every decreased degree on the outside temperature. Although at the moment the most popular heating systems are old fashioned fireplaces, stoves and cookers, its becoming to change with the coming of solar heating sytems and heat pumps.
its been 50 years now and you won’t believe the noise they made) . Today, we have not been able to acquire the technology to build our own phone systems. I can say with certainty we don’t even know or understand the technology behind the telephone system. No African countries manufacture the main telephone equipment systems; we don’t manufacture the receivers, we don’t manufacture telephone cables whether the old or the new fibre-optic sytems. Everywhere now in Africa, the cellular phone is the new toy for our people. We know how to dial the phone and speak to the other person on the other end. Apart from that, we don’t have a clue as to the knowledge behind this technological breakthrough. The Chinese, the Indians, without even mentioning the Japanese who control most of the technological knowledge on telecommunications, have acquired their own systems by ensuring that their people
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