IX. Give Ukrainian equivalents of the following word-combinations:
Free electron, semiconductor materials, electronic semiconductor, chemical elements, metallic oxides, phenomenon of semiconductivity, quantum theory, electron vacancy, metallic crystal, basic electrical charge, thermal vibration, high current, intrinsic conduction, ionic semiconductor, crystal framework.
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What is a computer?
A computer is a machine in many ways similar to other machines. It run on electricity. It contains a number of parts that work together. It's designed to perform certain tasks.
So far we could just as easily be describing a hairdryer, a power drill, or an electric lawnmower as a computer What is it that makes the computer special?
Several things. First, computers are fast. Not sixty-miles-per-hour fast. Blink-of-an-eye fast. Think about this: A "slow-computer can add hundreds of thousands of numbers in one second More powerful computers can add millions of numbers per second. In fact, when computer users discuss computer speed, they often don't even use the word second. They talk in terms of microseconds or nanoseconds. How small a unit of time do these terms refer to? Well – a second contains one million microseconds ... or one billion nanoseconds.
Besides being incredibly fast, computers are also extremely reliable. The average person using a pencil and paper to do arithmetic might make one or more mistakes in an hour. After several hours of work, the person would get tired and probably make more mistakes. By comparison, a computer can do arithmetic more quickly and more accurately, and it can continue working for hours or days at a time. Long after any human would have fallen asleep at his or her desk, the computer would still be calculating along – without so much as a yawn!
A third feature of computers that makes them unique machines is that they can receive, store and use information and instructions that you give them. What other machines can you think of that are able to do all that? (Careful, now — don't include machines containing microprocessors!) Can an ordinary mechanical typewriter, for example, remember tomorrow the letter you type today? A computer can — and, at your command, it can reproduce that same letter ten times, addressed to ten different people!
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What Do Economists Do?
We
have seen that economics deals with the problems of scarcity and
choice that nave faced societies and nations throughout history, but
the development of modern economics began in the 17th century. Since
that time economists have developed - nods for studying and
explaining how
available economic resources. Large corporations use economists to
study the ways they do business and to suggest methods for making
more efficient use of their employees, equipment, factories and other
resources. The United States government also employs economists to
study economic problems and to suggest ways to solve them.
You will discover that economists deal with two worlds: the "world that is" and the "world that ought to be, "Economists have developed and generally agree on basic economic principles and models that try to explain or describe the "world that is." An economic model is any simplified statement, diagram, or formula used to understand economic events. For example, economists can use basic principles like the laws of supply and demand and simple economic models to predict that the price of coffee in the United States will go up after a freeze destroys much of the Brazilian coffee crop. All economists would agree that the freeze would result in a price increase, but predicting the size of the increase would depend on the quality of the economist's model.
In many cases, however, economic issues cannot be solved with theories and models alone. Solutions to these problems involve opinion, politics, and personal values. For example, what ought to be done about the high rate of teenage unemployment? Economists will agree that unemployment is bad. As a solution to that problem, one economist might propose that government create jobs for teenagers. Another will oppose this step, suggesting instead that the problem of teenage unemployment would be solved if employers were allowed to pay teenagers lower wages than they must pay adult workers.