51. Unlike most of the world's volcanoes, they are not always found at the boundaries of the great drifting plates that make up the earth's surface; on the contrary, many of them lie deep in the interior of a plate.
52. The relative motion of the plates carrying these continents has been constructed in detail, but the motion of the plates with respect to another cannot readily be translated into motion with respect to the earth's interior.
[参考译文] 跟世界上的大多数火山不同的是,它们(热点)并不总是在由构成地球表面巨大漂流板块之间的边界上出现;相反,它们中有许多位于一个板块较纵深的内部
53. As the dome grows, it develops seed fissures (cracks); in at least a few cases the continentmay break entirely along some of these fissures, so that the hot spot initiates the formation of a new ocean.
[参考译文] 暂缺
54. While warnings are often appropriate and necessary--the dangers of drug interactions, for example--and many are required by state or federal regulations, it isn't clear that they actually protect the manufacturers and sellers from liability if a customer is injured.
55. At the same time, the American Law Institute--a group of judges, lawyers, and academics whose recommendations carry substantial weight--issued new guidelines for tort law stating that companies need not warn customers of obvious dangers or bombard them with a lengthy list of possible ones.
56. In the past year, however, software companies have developed tools that allow companies to "push" information directly out to consumers, transmitting marketing messages directly to targeted customers.
57. The examples of Virtual Vineyards, Amazon.com, and other pioneers show that a Web site selling the right kind of products with the right mix of interactivity, hospitality, and security will attract online customers.
58. An invisible border divides those arguing for computers in the classroom on the behalf of students' career prospects and those arguing for computers in the classroom for broader reasons of radical education reform.
59. Rather, we have a certain conception of the American citizen, a character who is incomplete if he cannot competently access how his livelihood and happiness are affected by things outside of himself.
60. Besides, this is unlikely to produce the needed number of every kind of professional in a country as large as ours and where the economy is spread over so many states and involves so many international corporations.
61.But,for a small group of students, professional training might be the way to go since well-developed skills, all other factors being equal, can be the difference between having a job and not.
62. Declaring that he was opposed to using this unusual animal husbandry technique to clone humans, he ordered that federal funds not be used for such an experiment-although no one had proposed to do so--and asked an independent panel of experts chaired by Princeton President Harold Shapiro to report back to the White House in 90 days with recommendations for a national policy on human cloning.
63. In a draft preface to the recommendations, discussed at the 17 May meeting, Shapiro suggested that the panel had found a broad consensus that it would be "morally unacceptable to attempt to create a human child by adult nuclear cloning".
64. Because current federal law already forbids the use of federal funds to create embryos (the earliest stage of human offspring before birth) for research or to knowingly endanger an embryo's life, NBAC will remain silent on embryo research.
65. If experiments are planned and carried out according to plan as faithfully as the reports in the science journals indicate, then it is perfectly logical for management to expect research to produce results measurable in dollars and cents.
66. It is entirely reasonable for auditors to believe that scientists who know exactly where they are going and how they will get there should not be distracted by the necessity of keeping one eye on the cash register while the other eye is on the microscope.
67. Nor, if regularity and conformity to a standard pattern are as desirable to the scientist as the writing of his papers would appear to reflect, is management to be blamed for discriminating against the "odd balls" among researchers in favor of more conventional thinkers who "work well with the team."
68. The grand mediocrity of today--everyone being the same in survival and number of off- spring--means that natural selection has lost 80% of its power in upper-middle-class India compared to the tribe.
69. When a new movement in art attains a certain fashion, it is advisable to find out what its advocates are aiming at, for, however farfetched and unreasonable their principles may seem today, it is possible that in years to come they may be regarded as normal.
70. With regard to Futurist poetry, however, the case is rather difficult, for whatever Futurist poetry may be even admitting that the theory on which it is based may be right--it can hardly be classed as Literature.
71. But it is a little upsetting to read in the explanatory notes that a certain line describes a fight between a Turkish and a Bulgarian officer on a bridge off which they both fall into the river--and then to find that the line consists of the noise of their falling and the weights of the officers, "Pluff! Pluff!" A hundred and eighty-five kilograms."
72. The coming of age of the postwar baby boom and an entry of women into the male- domiated job market have limited the opportunities of teen-agers who are already questioning the heavy personal sacrifices involved in climbing Janpan's rigid social ladder to good schools and jobs.
73. Last year Mitsuo Setoyama, who was then education minister, raised eyebrows when he argued that liberal reforms introduced by the American occupation authorities after World WarII had weakened the "Japanese morality of respect for parents".
74. With economic growth has come centralization: fully 76 percent of Japan's 119 million citizens live in cities where community and the extended family have been abandoned in favor of isolated, tow-generation households.
75. If the tradition of ambition is to have vitality, it must be widely shared; and it especially must be highly regarded by people who are themselves admired, the educated not least among them.