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以下疾病中较易出现心绞痛和晕厥的是
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Passage Four Science is an enterprise concerned with gaining information about causality, or the relationship between cause and effect. A simple example of a cause is the movement of a paddle as it strikes a ping-pong ball; the effect is the movement of the ball through the air. In psychology and other sciences, the word "cause" is often replaced by the term "independent variable". This term implies that the experimenter is often "free" to vary the independent variable as he or she desires (for example, the experimenter can control the speed of the paddle as it strikes the ball). The term "dependent variable" replaces the word "effect", and this term is used because the effect depends on some characteristic of the independent variable (the flight of the ball depends on the speed of the paddle). The conventions of science demand that both the independent and dependent variables be observable events, as is the case in the ping-pong example. In the case of biorhythm theory, the independent variable is the number of days that have elapsed between a person’s date of birth and some test day. The dependent variable is the person’s level of performance on some specified task on the test day. Notice that although the experimenter is not free to choose a birthday for a given individual, persons with different dates of birth can be tested on the same day, or a single subject can be tested on several different days. In order to predict the relationship between independent and dependent variables, many scientific theories make use of what are called intervening variables. Intervening variables are purely theoretical concepts that cannot be observed directly. To predict the flight of a ping-pong ball, Newtonian physics relies on a number of intervening variables, including force, mass, air resistance, and gravity. You can probably anticipate that the intervening variables of biorhythm theory are the three bodily cycles with their specified time periods. It should be emphasized that not all psychological theories include intervening variables, and some psychologists object to their use precisely because they are not directly observable. The final major component of a scientific theory is its syntax, or the rules and definitions that state how the independent and dependent variables are to be measured, and that specify the relationships among independent variables, intervening variables, and dependent variables. It is the syntax of biorhythm theory that describes how to use a person’s birthday to calculate the current status of the three cycles. The syntax also relates the cycles to the dependent variable, performance, by stating that positive cycles should cause high levels of performance whereas low or critical cycles should cause low performance levels. To summarize, the components of a scientific theory can be divided into four major categories: independent variables, dependent variables, intervening variables, and syntax. Based on the passage, causality may have the meaning that ______.
German Chancellor (首相) Otto Von Bismarck may be most famous for his military and diplomatic talent, but his legacy (遗产) includes many of today’s social insurance programs. During the middle of the 19th century, Germany, along with other European nations, experienced an unprecedented rash of workplace deaths and accidents as a result of growing industrialization. Motivated in part by Christian compassion (怜悯) for the helpless as well as a practical political impulse to undercut the support of the socialist labor movement, Chancellor Bismarck created the world’s first workers’ compensation law in 1884.By 1908, the United States was the only industrial nation in the world that lacked workers’ compensation insurance. America’s injured workers could sue for damages in a court of law, but they still faced a number of tough legal barriers. For example, employees had to prove that their injuries directly resulted from employer’s negligence and that they themselves were ignorant about potential hazards in the workplace. The first state workers’ compensation law in this country was passed in 1911, and the program soon spread throughout the nation.After World War Ⅱ, benefit payments to American workers did not keep up with the cost of living. In fact, real benefit levels were lower in the 1970s than they were in the 1940s, and in most states the maximum benefit was below the poverty level for a family of four. In 1970, President Richard Nixon set up a national commission to study the problems of workers’ compensation. Two years later, the commission issued 19 key recommendations, including one that called for increasing compensation benefit levels to 100 percent of the states’ average weekly wages.In fact, the average compensation benefit in America has climbed from 55 percent of the states’ average weekly wages in 1972 to 97 percent today. But, as most studies show, every 10 percent increase in compensation benefits results in a 5 percent increase in the numbers of workers who file for claims. And with so much more money floating in the workers’ compensation system, it’s not surprising that doctors, and lawyers have helped themselves to a large slice of the growing pie. After 1972, workers’ compensation insurance in the U.S. became more favorable to workers so that （）
In our society the razor of necessity cuts close. You must make a buck to survive the day. You must work to make a buck. The job is often a chore, rarely a delight. No matter how demeaning the task, no matter how it dulls the senses or breaks the spirit, one must work. Lately there has been a questioning of this "work ethic", especially by the young. Strangely enough, it has touched off profound grievances in others hitherto silent and anonymous.Unexpected precincts are being heard from in a show of discontent by blue collar and white. On the evening bus the tense, pinched faces of young file clerks and elderly secretaries tell us more than we care to know. On the expressways middle-management men pose without grace behind their wheels, as they flee city and job.In all, there is more than a slight ache. And there dangles the impertinent question: Should there not be another increment, earned though not yet received, to one’s daily work—an acknowledgment of a man’s being In fact, what all of us are looking for is a calling, not just a job. Jobs alone are not being enough for people. The "work ethic" in the first paragraph can be interpreted as （）
Motorola Inc. , the world’s second-largest mobile phone maker, will begin selling all of the technology needed to build a basic mobile phone to outside manufacturers, in a key change of strategy. The inventor of the cell phone, which has been troubled by missteps compounded by a recent industry slump in sales, is trying to become a neutral provider of mobile technology to rivals, with an eye toward fostering a much larger market than it could create itself. The Chicago area-based company, considered to have the widest range of technologies needed to build a phone, said it planned to make available chips, a design layout for the computer board, software, development tools and testing tools. Motorola has previously supplied mobile phone manufacturers with a couple of its chips, but this is the first time the company will offer its entire line of chips as well as a detailed blueprint. Mobile phones contain a variety of chips and components to control power, sound and amplification. Analysts said they liked the new strategy but were cautious about whether Motorola’s mobile phone competitors would want to buy the technology from a rival.The company, long known for its top-notch (等级) engineering culture, is hoping to profit from its mobile phone technology now that the basic technology to build a mobile phone has largely become a commodity. Motorola said it will begin offering the technology based on the next-generation GPRS (Global Packet Radio Service) standard because most mobile phone makers already have technology in place for current digital phones. GPRS offers faster access to data through "always on" network connections, and customers are charged only for the information they retrieve, rather than the length of download.Burgess said the new business will not conflict with Motorola’s own mobile phone business because the latter will remain competitive by offering advanced features and designs. Motorola’s phones have been criticized as being too complicated and expensive to manufacture, but Burgess said Motorola will simplify the technology in the phones by a third. In addition to basic technology, Burgess said, Motorola would also offer additional features such as Blueteeth, a technology that allows wireless communications at a short distance, and Global Positioning System, which tracks the user’s whereabouts, and MP3 audio capability. The word "slump" in the first paragraph may be replaced by （）
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