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【F1】Computer science as an independent discipline dates to only about 1960, although the electronic digital computer that is the object of its study was invented some two decades earlier.The roots of computer science lie primarily in the related fields of electrical engineering and mathematics. Electrical engineering provides the basics of circuit design—namely, the idea that electrical impulses input to a circuit can be combined to produce arbitrary outputs.【F2】The invention of the transistor and the miniaturization of circuits, along with the invention of electronic, magnetic, and optical media for the storage of information, resulted from advances in electrical engineering and physics.Mathematics is the source of one of the key concepts in the development of the computer—the idea that all information can be represented as sequences of zeros and ones. In the binary number system, numbers are represented by a sequence of the binary digits 0 and 1 in the same way that numbers in the familiar decimal system are represented using the digits 0 through 9.【F3】The relative ease with which two states(e. g. , high and low voltage)can be realized in electrical and electronic devices led naturally to the binary digit, or bit, becoming the basic unit of data storage and transmission in a computer system.The Boolean algebra developed in the 19th century supplied a formalism for designing a circuit with input values of 0"s and 1 "s(false or true, respectively, in the terminology of logic)to yield any desired combination of 0" s and l"s as output.【F4】Theoretical work on computability, which began in the 1930s, provided the needed extension to the design of whole machines; a milestone was the 1936 specification of the conceptual Turing machine(a theoretical device that manipulates an infinite string of 0" s and 1" s)by the British mathematician Alan Turing and his proof of the model"s computational power.Another breakthrough was the concept of the stored-program computer, usually credited to the German-American mathematician John von Neumann.【F5】This idea—that instructions as well as data should be stored in the computer"s memory for fast access and execution—was critical to the development of the modern computer. Previous thinking was limited to the calculator approach, in which instructions are entered one at a time. 【F1】

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【F1】Computer science as an independent discipline dates to only about 1960, although the electronic digital computer that is the object of its study was invented some two decades earlier.The roots of computer science lie primarily in the related fields of electrical engineering and mathematics. Electrical engineering provides the basics of circuit design—namely, the idea that electrical impulses input to a circuit can be combined to produce arbitrary outputs.【F2】The invention of the transistor and the miniaturization of circuits, along with the invention of electronic, magnetic, and optical media for the storage of information, resulted from advances in electrical engineering and physics.Mathematics is the source of one of the key concepts in the development of the computer—the idea that all information can be represented as sequences of zeros and ones. In the binary number system, numbers are represented by a sequence of the binary digits 0 and 1 in the same way that numbers in the familiar decimal system are represented using the digits 0 through 9.【F3】The relative ease with which two states(e. g. , high and low voltage)can be realized in electrical and electronic devices led naturally to the binary digit, or bit, becoming the basic unit of data storage and transmission in a computer system.The Boolean algebra developed in the 19th century supplied a formalism for designing a circuit with input values of 0"s and 1 "s(false or true, respectively, in the terminology of logic)to yield any desired combination of 0" s and l"s as output.【F4】Theoretical work on computability, which began in the 1930s, provided the needed extension to the design of whole machines; a milestone was the 1936 specification of the conceptual Turing machine(a theoretical device that manipulates an infinite string of 0" s and 1" s)by the British mathematician Alan Turing and his proof of the model"s computational power.Another breakthrough was the concept of the stored-program computer, usually credited to the German-American mathematician John von Neumann.【F5】This idea—that instructions as well as data should be stored in the computer"s memory for fast access and execution—was critical to the development of the modern computer. Previous thinking was limited to the calculator approach, in which instructions are entered one at a time. 【F3】

Despite the basic biological, chemical, and physical similarities found in all living things, a diversity of life exists not only among and between species but also within every natural population. The phenomenon of diversity has had a long history of study because so many of the variations that exist in nature are visible to the eye. 【F1】It has been suggested that sexual reproduction became the dominant type of reproduction among organisms because of its inherent advantage of variability, which is the mechanism that enables a species to adjust to changing conditions.New variations are potentially present in genetic differences, but how preponderant a variation becomes in a gene pool depends upon the number of offspring the mutants or variants produce(differential reproduction).【F2】It is possible for a genetic novelty(new variation)to spread in time to all members of a population, especially if the novelty enhances the population"s chances for survival in the environment in which it exists.Thus, when a species is introduced into a new habitat, it either adapts to the change by natural selection or by some other evolutionary mechanism or else it eventually dies off. Because each new habitat means new adaptations, habitat changes have been responsible for the millions of different kinds of species and for the heterogeneity within each species. The total number of animal and plant species is estimated at between 2,000,000 and 4,500,000; authoritative estimates of the number of extinct species range from 15,000,000 up to 16,000,000,000.【F3】Although the use of classification as a means of producing some kind of order out of this staggering number of different types of organisms appears as early as the book of Genesis—with references to cattle, beasts, fowl, creeping things, trees, etc. —the first scientific attempt at classification is attributed to the Greek philosopher Aristotle, who tried to establish a system that would indicate the relationship of all things to each other.He arranged everything along a scale, or "ladder of nature", with nonliving things at the bottom; plants were placed below animals, and man was at the top.【F4】Other schemes that have been used for grouping species include large anatomical similarities, such as wings or fins, which indicate a natural relationship, and also similarities in reproductive structures.【F5】At the present time taxonomy is based on two major assumptions; one is that similar body construction can be used as a criterion for a classification grouping; the other is that, in addition to structural similarities, evolutionary and molecular relationships between organisms can be used as a means for determining classification. 【F2】

李某是某村村长，1996年秋，将已初中毕业在家务农的女青年乔某安排到本村小学做代课教师。李某多次到学校找乔某，在威逼利诱之下，乔某与其发生了性关系。其后，李某又多次纠缠乔某，二人保持不正当关系达两年之久。乔某慑于李某的淫威，又怕丢面子，给家人抹黑，一直将此事隐瞒。1999年春，乔某辞职，回家务农。乔某回家后，李某又不断去乔某家，乔某忍无可忍将此事告诉家人。1999年6月5日，李某又来乔某家，欲与乔某发生性关系，乔某坚决不肯，李某欲强奸乔某，二人厮打起来。住在西间的乔父听见有声音，来到现场，见李某欲强暴其女，便手持木棍，来到李某背后将李某打昏在地，用绳子将李某捆住后，到派出所报案。乔某想到这几年受到的侮辱，越发痛恨李某，顺手拿起床边的剪刀向李某的阴部、腹部连扎数下，致李某重伤。试分析： (1)乔某父亲的行为是否属于正当防卫为什么 (2)乔某的行为如何定性为什么

【F1】Computer science as an independent discipline dates to only about 1960, although the electronic digital computer that is the object of its study was invented some two decades earlier.The roots of computer science lie primarily in the related fields of electrical engineering and mathematics. Electrical engineering provides the basics of circuit design—namely, the idea that electrical impulses input to a circuit can be combined to produce arbitrary outputs.【F2】The invention of the transistor and the miniaturization of circuits, along with the invention of electronic, magnetic, and optical media for the storage of information, resulted from advances in electrical engineering and physics.Mathematics is the source of one of the key concepts in the development of the computer—the idea that all information can be represented as sequences of zeros and ones. In the binary number system, numbers are represented by a sequence of the binary digits 0 and 1 in the same way that numbers in the familiar decimal system are represented using the digits 0 through 9.【F3】The relative ease with which two states(e. g. , high and low voltage)can be realized in electrical and electronic devices led naturally to the binary digit, or bit, becoming the basic unit of data storage and transmission in a computer system.The Boolean algebra developed in the 19th century supplied a formalism for designing a circuit with input values of 0"s and 1 "s(false or true, respectively, in the terminology of logic)to yield any desired combination of 0" s and l"s as output.【F4】Theoretical work on computability, which began in the 1930s, provided the needed extension to the design of whole machines; a milestone was the 1936 specification of the conceptual Turing machine(a theoretical device that manipulates an infinite string of 0" s and 1" s)by the British mathematician Alan Turing and his proof of the model"s computational power.Another breakthrough was the concept of the stored-program computer, usually credited to the German-American mathematician John von Neumann.【F5】This idea—that instructions as well as data should be stored in the computer"s memory for fast access and execution—was critical to the development of the modern computer. Previous thinking was limited to the calculator approach, in which instructions are entered one at a time. 【F5】