¡¡¡¡AURA solves a program by drawing conclusions from a given set of facts about the problem. The program reaches logical conclusions flawlessly as it uses various types of reasoning and solves almost all problems by using sophisticated techniques to find a contradiction.

¡¡¡¡One generally starts with a set of assumptions and adds a statement that the goal is unreachable. For example, if the problem is to test a safety system that automatically shuts down a nuclear reactor when instruments indicate a problem, AURA is told that the system will not shut the reactor down under those circumstances. If AURA finds a contradiction between the statement and the system¬ðs design assumptions, then this aspect of the reactor¬ðs design has been proved satisfactory. This strategy lets AURA concentrate on the problem at hand and avoid the many fruitless steps required to explore the entire theory underlying the problem.

¡¡¡¡The chief use for AURA at this time is for electronic circuit design validation, but a number of other uses will arise. For example, there already exist ¡°expert systems¡± that are specialª²purpose programs designed to automate reasoning in a specific area such as medical diagnosis. These expert systems continue to improve and have an indefinite life span. Moreover, they can be duplicated for pennies. A human who can expertly predict where to drill for oil is in great demand. A program that can predict equally well would be invaluable and could be duplicated any number of times.

¡¡¡¡Will the computer replace the human being? It seems likely that computer programs will reproduce more clever programs and more efficient components. Reasoning programs will also analyze their own progress, learn from their attempts to solve a problem. Such programs will assist, rather than replace, humans. Reasoning assistants will enable human minds to turn to deeper and far more complex ideas, which will be partially formulated and then checked for reasoning flaws by a reasoning program. Many errors will be avoided.21. The author suggests in Par.1 that humans are

¡¡¡¡\[A\] liable to irrational thinking.\[B\] apt to err in simple counting.

¡¡¡¡\[C\] prone to memory dysfunction.\[D\] subject to unwitting reasoning.

¡¡¡¡22. The way AURA works in is to

¡¡¡¡\[A\] explore the faults in designing.\[B\] discover the bugs in a program.

¡¡¡¡\[C\] state against the set suppositions.\[D\] make assumptions by reasoning.

¡¡¡¡23. All of the following are mentioned as areas for AURA EXCEPT

¡¡¡¡\[A\] electronic engineering.\[B\] detection of fossil fuels.

¡¡¡¡\[C\] identification of diseases.\[D\] complicated mental logic.

¡¡¡¡24. All of the following are advantages of expert programs EXCEPT

¡¡¡¡\[A\] they can be duplicated infinitely.\[B\] they are featured by selfª²analysis.

¡¡¡¡\[C\] they may be enriched in contents.\[D\] they are reproduced almost free.

¡¡¡¡25. The best title for the text seems to be

¡¡¡¡\[A\] Practical Uses of Computers.\[B\] Suggested Applications for AURA.

¡¡¡¡\[C\] The Technical Perfection of AURA.\[D\] Computer Aid to Human Reasoning.

¡¡¡¡Text2

¡¡¡¡Half the world¬ðs population will be speaking or learning English by 2015,researchers say.Two billion people are expected to start learning English within a decade and three billion will speak it,says a British Council estimate.

¡¡¡¡Other languages,such as French,risk becoming the casualties of this ¡°linguistic globalization¡±.But the boom will be over by 2050 and the Englishª²language teaching industry will have become a victim of its own success,says David Graddol,author of the report,The Future of English.

¡¡¡¡Mr.Graddol¬ðs research was based on a computer model developed to estimate demand for Englishª²language teaching around the world.The lecturer,who has worked in education and language studies at the Open University for the past 25 years,said the model charted likely student numbers through to 2050.

¡¡¡¡It was compiled by looking at various estimates from the United Nations Education,Scientific and Cultural Organization (Unesco) on education provision,demographic projections,government education policies and international student mobility figures.The impact of educational innovations and other developments affecting the world population including the Chinese government¬ðs policy of one baby per family were also factored in.

¡¡¡¡Based on its findings,Mr.Graddol has predicted that the world is about to be hit by a tidal wave of English.¡°Many governments,especially in countries which have relatively recently gained independence,are introducing the teaching of English under a utilitarian banner.¡±

¡¡¡¡¡°But English predominates in the business world,and for such countries to be able to compete for work,including lucrative (profitable) outsourcing contracts,English is being pushed heavily from kindergarten on.¡±