单选题 Questions 31-40
Questions 31-32
Choose the correct letter, A, B or C.
单选题 Compared to harvesting on land, harvesting at sea is
  • A. more difficult.
  • B. less difficult.
  • C. the same.
【正确答案】 C
【答案解析】[解析] 31-40 Students, I hope this first lecture which I've called "The Uses of Oceanography" will provide a helpful starting point for our studies this semester. In order to be a valid area of study it has been said that the scientific study of the sea or oceanography, as we call it, must point to the practical benefits that can be gained for humankind. There is no doubt—many are the benefits which have been identified as a result of study in this field. Firstly, through careful study, oceanography helps us to determine where new raw materials for the future may come from—such as where new foods, for example, may be harvested. Certainly to reap the harvest of the ocean is {{U}}just as difficult{{/U}} as it is Q31 on the land —microscopic plants and animals or plankton are neither easy to gather nor edible for humans. Fortunately, our marine creatures do an excellent job at both gathering and eating so we must continue to go out into the oceans and confront the often difficult oceanic conditions in an attempt to capture them for food. Of course, even in the most fertile areas, stocks of profitable and edible fish are not inexhaustible. In many areas around the world, limits are placed on numbers of fish that can be caught. Improving our understanding of marine species' behaviour is therefore a dominant area of study for oceanographers. For hundreds of years, the ocean has been a cheap highway for commerce but the challenge for those who travel it has always been to do so safely. Oceanographers therefore attempt to bring some {{U}}predictability to the movement of currents{{/U}} Q32 as well as the wields that blow and the effect these have on the waves that are generated. Early oceanographers such as Edward Forbes, a native of the {{U}}Isle of Man{{/U}} and Q33 considered by many to be {{U}}the founder of the science of oceanography{{/U}}, was the Q34 person to lay the foundation for British government support of oceanography in the mid 19th century. Another of Forbes' contemporaries, Irishman J. Vaughan Thomson, collected and studied marine plankton off the Irish coast in 1828. In addition to marine life, Thomson's interests were in the {{U}}tidal patterns{{/U}} and Q35 currents of the ocean. Another of the early professional naturalists that made significant contributions to marine biology was {{U}}Charles Darwin{{/U}}. Darwin, Q36 most famous for his later works on theories of evolution, was commissioned early in life as a naturalist on H.M.S. Beagle expeditions in the early 1800s. {{U}}The Englishman{{/U}} collected and studied numerous marine organisms during Q37 this famous voyage, which eventually led to his subsidence theory of coral reef formation. According to this theory fringing reefs form along the edges of an island and then, as the island subsides, a barrier reef is created. So we see that early oceanographers were interested in bringing predictability to the ebb and flow of the vast ocean. With industry pumping out more and more waste, another area in which oceanographers have busied themselves is in the use of the ocean as a means of waste disposal. In an attempt to discover a satisfactory answer to the question, the processes of {{U}}diffusion and mixing{{/U}}, and the manner in which they depend on Q39 waves, tides and currents remains a focused area of study. Nuclear waste has also been an important area. Oceanographers are currently studying the {{U}}effects of the{{/U}} Q38 {{U}}burial of waste{{/U}} into the mud of remote ocean sites. The nuclear waste is packed into metal containers and transported via ship to a selected burial site. There is always debate concerning whether seabed disposal of radioactive waste is simply dumping today with little thought for tomorrow. As we cannot predict the future, this question is a difficult one to answer. Instead of merely burying the nuclear waste, {{U}}other means of disposal{{/U}} must be explored. This situation provides a Q40 strong future challenge for oceanographers and ensures their need for many years to come. In next weeks' lecture we will continue...
单选题 Oceanographers help sailors by
  • A. studying the movement of ships.
  • B. researching ocean temperatures.
  • C. predicting currents and winds.
【正确答案】 C
【答案解析】