题目内容
Water is the oldest form of transport. The original sailing vessels were replaced by steamboats in the early 1800s and by diesel power in the 1920s. A distinction is generally made between deepwater and navigable inland water transport. Domestic commerce centers on tile Great Lakes, canals, and navigable rivers. In 1975 water transport accounted for 22.6 percent of total intercity tonnage. Its relative share of intercity tonnage was 31.3 percent in 1947 and 31.7 percent in 1958. Tonnage declined to 27.9 percent in 1965 but increased by 1970 to 28.4 percent. This short-term increase did not stabilize. Market share dropped by 5.8 percent by 1975. Forecasted market share by 1985 is 18.4 percent of total intercity tonnage. The water transport share of revenue has been less than 2 percent of intercity freight revenue since 1955. The exact miles of improved waterways in operation depend in part on whether coastwise and intercostal shipping are included. Approximately 26,000 miles of improved inland waterways were operated in 1975. Fewer miles of improved inland waterways exist than of any other transportation mode. The main advantage of water transport is the capacity to move extremely large shipments. Deepwater vessels are restricted in operation, but diesel-towed barges have a fair degree of flexibility. In comparison to rail and highway, water transport ranks in the middle with respect to fixed cost. The fixed cost of operation is greater than that of motor carriers but less than that of railroads. The main disadvantage of water is the limited degree of flexibility and the low speeds of transport. Unless the source and destination of the movement are adjacent to a waterway, supplemental haul by rail or truck is required. The capability of water to transport large tonnage at low variable cost places this mode of transport in demand when low freight rates are desired and speed of transit is a secondary consideration. Freight transported by inland water leans heavily to mining and basic bulk commodities, such as chemicals, cement, and selected agricultural products. In addition to the restrictions of navigable waterways, terminal facilities for bulk arid dry cargo storage and load-unload devices limit the flexibility of water transport. Labor restrictions on loading and unloading at dock level create operational problems and tend to reduce the potential range of available traffic. Finally, a highly competitive situation has developed between railroads and inland water carriers in areas where parallel routings exist. Inland and Great Lakes water transport will continue to be a viable alternative for future logistical system design. The full potential of the St. Lawrence Seaway has not yet been realized with respect to domestic freight. The slow passage of inland river transport can provide a form of warehousing in transit if fully integrated into overall system design. Improvements in ice-breaking equipment appear on the verge of eliminating the seasonal limitations of water transport. Which of the following statements is true according to the article
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Think of all the criminals who have killed, all the soldiers who have killed; consider the mass murder of Jews in Nazi Germany. Is there something inside human beings that allows us to take part in this sort of violence, or were these people swept along by the situation Stanley Milgram, a New York psychologist, designed an experiment to find answers to this question, paying adult males four and a half dollars to act the role of "teacher" in a complicated experiment. The "teachers" were to ask questions of a "learner", a middle-aged man in another room. If the learner gave an incorrect answer, the teacher was instructed to turn a knob to send an electric current to the learner’s chair. There were thirty positions on the control knob, with the shocks ranging from 15 to 450 volts, the last position marked "Danger: Severe Shock". The teachers were told to increase the severity of the shock with each incorrect response. With the first few shocks, the learner could be heard over the intercom, grunting and moaning. When the dial reached 150, he demanded that the experiment be ended; shortly afterwards, at 180 volts, he began to complain of the pain. At 300 volts, he complained about his heart condition, screamed, and no longer responded to the questions; but the teachers who complanined about their roles in the experiment were told the experiment had to continue. According to the rules, the learner’s failure to respond was an "error", so he must be shocked. A group of psychiatrists was asked for predictions. Certainly, they said, most people would not punish the victim beyond 150 volts. Furthermore, they predicted fewer than four percent would persist up to 300 volts; only abnormal individuals--less than one tenth of a percent--would proceed to 450 volts. And, in fact, nearly every "teacher" did protest--each became concerned that he might injure the learner, and many said they could not continue to follow instructions. At 180 volts, one "teacher" said, "He’s hollering. He can’t stand it; what if anything happens to him I mean who is going to take responsibility if anything happens to that gentleman" When the experimenter said he would accept responsibility, the teacher meekly responded, "All right." Some teachers, alarmed by the silence in the next room, called out to the learner to answer so they wouldn’t have to continue shocking him. In fact, most of the teachers protested, but the important thing is that they did not disobey their instruction. Sixty-two percent of all the subjects delivered shocks all the way up to 450 volts--the average highest shock was 370 volts. Of course, the learner was not being shocked. Even his screams were tape-recorded. But this experiment and similar variations of it have been repeated several times, and the results are invariably the same: in the presence of authority, in a situation governed by rules. Personality tests given to the subjects who delivered the shocks of 450 volts show that they are not abnormal or sick in any way. They’re exactly like the rest of us. We can conclude from the passage that ______.
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