试题库在线考试题库-历年真题模拟试题及答案-考博英语在线试题测试中心-希赛网

题库

首页 > 题库 > 国防科技大学

The activists’ energetic work in the service of both woman suffrage and the temperance movement in the late nineteenth century ______ the assertion that the two movements were inimical.

Although the number of reported volcanic eruptions has risen exponentially since 1850, this indicates not increasing volcanic activity but rather more widespread and ______ record keeping.

What these people want is a ______ existence—more food, better shelter and peace.

You comment that I seem relaxed today. Are you ______that I’m usually uptight?

Social scientists have established fairly clear-cut ______ that describe the appropriate behavior of children and adults, but there seems to be confusion about what constitutes appropriate behavior for adolescents.

A human is quite a ______ creature, for the gloss of rationality that covers his or her fears and insecurity is thin and often easily breached.

Ethologists are convinced that many animals survive through learning—but learning that is indicated by their genetic programming, learning as thoroughly as the most ______ instinctive of behavioral responses.

If a species of parasite is to survive, the host organisms must live long enough for the parasite to reproduce; if the host species becomes ______, so do its parasites.

Although is unusual to denounce museum-goers for not painting, it is quite common, even top those, who are unenthusiastic about sports, to criticize spectators for athletic ______.

In spite of the rain, the ______ spectators waited patiently for the delayed start of the game.

We live in a(n) ______ society which views success primarily in terms of material possessions.

One sign that she is making progress in art courses such as painting or photography is______ she begins to realize how much there is to learn.

We rarely perceive more than a minute ______ of the sights and sounds that fall upon our sense organs; the great majority pass us by.

You have to have your library card with you if you want to borrow books, ______?

Nuclear science should be developed to benefit the people ______ harm them.

—Excuse me, sir. Would you do me a favor?—Of course. What is it?—I ______ if you could tell me how to fill out this form.

There is increasing evidence that the impacts of meteorites have had important effects on Earth, particularly in the field of biological evolution. Such impacts continue to pose a natural hazard to life on Earth. Twice in the twentieth century, large meteorite objects are known to have collided with Earth.If an impact is large enough, it can disturb the environment of the entire Earth and cause an ecological catastrophe. The best-documented such impact took place 65 million years ago at the end of the Cretaceous period of geological history. This break in Earth’s history is marked by a mass extinction, when as many as half the species on the planet became extinct. While there are a dozen or more mass extinctions in the geological record, the Cretaceous mass extinction has always intrigued paleontologists because it marks the end of the age of the dinosaurs. For tens of millions of years, those great creatures had flourished. Then, suddenly, they disappeared. The body that impacted Earth at the end of the Cretaceous period was a meteorite with a mass of more than a trillion tons and a diameter of at least 10 kilometers. Scientists first identified this impact in 1980 from the worldwide layer of sediment deposited from the dust cloud that enveloped the planet after the impact. This sediment layer is enriched in the rare metal iridium and other elements that are relatively abundant in a meteorite but very rare in the crust of Earth. Even diluted by the terrestrial material excavated from the crater, this component of meteorites is easily identified. By 1990 geologists had located the impact site itself in the Yucat region of Mexico. The crater, now deeply buried in sediment, was originally about 200 kilometers in diameter.This impact released an enormous amount of energy, excavating a crater about twice as large as the lunar crater Tycho. The explosion lifted about 100 trillion tons of dust into the atmosphere, as can be determined by measuring the thickness of the sediment layer formed when this dust settled to the surface. Such a quantity of material would have blocked the sunlight completely from reaching the surface, plunging Earth into a period of cold and darkness that lasted at least several months. The explosion is also calculated to have produced vast quantities of nitric acid and melted rock that sprayed out over much of Earth, starting widespread fires that must have consumed most terrestrial forests and grassland. Presumably, those environmental disasters could have been responsible for the mass extinction, including the death of the dinosaurs.Several other mass extinctions in the geological record have been tentatively identified with large impacts, but none is so dramatic as the Cretaceous event. But even without such specific documentation, it is clear that impacts of this size do occur and that their results can be catastrophic. What is a catastrophe for one group of living things, however, may create opportunities for another group. Following each mass extinction, there is a sudden evolutionary burst as new species develop to fill the ecological niches opened by the event.Impacts by meteorites represent one mechanism that could cause global catastrophes and seriously influence the evolution of life all over the planet. According to some estimates, the majority of all extinctions of species may be due to such impacts. Such a perspective fundamentally changes our view of biological evolution. The standard criterion for the survival of a species is its success in competing with other species and adapting to slowly changing environments. Yet an equally important criterion is the ability of a species to survive random global ecological catastrophes due to impacts.Earth is a target in a cosmic shooting gallery, subject to random violent events that were unsuspected a few decades ago. In 1991 the United States Congress asked NASA to investigate the hazard posed today by large impacts on Earth. The group conducting the study concluded from a detailed analysis that impacts from meteorites can indeed be hazardous. Although there is always some risk that a large impact could occur, careful study shows that this risk is quite small.62. In paragraph 2, why does the author include the information that dinosaurs had flourished for tens of millions of years and then suddenly disappeared?63. Which of the following can be inferred from the passage about the location of the meteorite impact in Mexico?64. The word “excavating” in Para.4 is closest in meaning to ____.65. Which of the following statements about the factors that are essential for the survival of a species is supported in Paragraph 6?

By education I mean the influence of the environment upon the individual to produce a permanent change in the habits of behavior, of thought and of attitude. It is in being thus susceptible to the environment that man differs from the animals, and the higher animals from the lower. The lower animals are influenced by the environment but not in the direction of changing their habits. Their instinctive responses are few and fixed by heredity. When transferred to an unnatural situation, such an animal is led astray by its instincts. Thus the ant-lion whose instinct implies it to bore into loose sand by pushing backward with abdomen, goes backwards on a plate of glass as soon as danger threatens, and endeavors, with the utmost exertions to bore into it. It knows no other mode of fight or if such a lonely animal is engaged upon a chain of actions and is interrupted, it either goes on vainly with the remaining actions (as useless as cultivating an unsown field) or dies in helpless inactivity. Thus a net-making spider which digs a burrow and rims it with a bastion of gravel and bits of wood, when removal from a half-finished home, will not begin again, though it will continue another burrow, even one made with a pencil.Advanced in the scale of evolution along such lines as these could only be made by the emergence of creatures with more and more complicated instincts. Such beings we know in the ants and spiders. But another line of advance was destined to open out a much more far-reaching possibility of which we do not see the end perhaps even in man. Habits, instead of being born ready-made (When they are called instincts and not habits at all) were left more and more to the formative influence of the environment, of which the most important factor was the parent who now cared for the young animal during a period of infancy in which vaguer instincts than those of the insects were modeled to suit surroundings which might be considerably changed without harm. This means, one might at first imagine, that gradually heredity becomes less and environment more important. But this is hardly the truth and certainly not the whole truth. For although fixed automatic responses like those of the insect-like creatures are no longer inherited, although selection for purification of that sort is no longer going on, yet selection for educability is very definitely still of importance. The ability to acquire habits can conceivably inherit just as much as can definite responses to narrow situations. Environment and heredity are in no case exclusive but always supplementary factors.58. Which of the following is the most suitable title for the passage?59. What can be inferred from the example of the ant-lion?60. Based on the example provided in the passage, we can tell that when a spider is removed to a new position where half of a net has been made, it will probably ____.61. Which of the following is true about habits?

Archaeological literature is rich in descriptions of pot making. Unlike modern industrial potters, prehistoric artisans created each of their pieces individually, using the simplest technology but demonstrating remarkable skill in making and adorning their vessels.The clay used in prehistoric pot making was invariably selected with the utmost care: often it was traded over considerable distances. The consistency of the clay was crucial: it was pounded meticulously and mixed with water to make it entirely even in texture. By careful kneading, the potter removed the air bubbles and made the clay as plastic as possible, allowing it to be molded into shape as the pot was built up, When a pot is fired, it loses its water and can crack, so the potter added a temper to the clay, a substance that helped reduce shrinkage and cracking.Since surface finishes provided a pleasing appearance and also improved the durability in day-to-day use, the potter smoothed the exterior surface of the pot with wet hands. Often a wet clay solution, known as a slip, was applied to the smooth surface. Brightly colored slips were often used and formed painted decorations on the vessel. In later times. Glazes came into use in some areas. A glaze is a form of slip that turns to a glasslike finish during high-temperature firing. When a slip was not applied, the vessel was allowed to dry slowly until the external surface was almost like leather in texture. It was then rubbed with a round stone or similar object to give it a shiny, hard surface. Some pots were adorned with incised or stamped decorations.Most early pottery was then fired over open hearths. The vessels were covered with fast-burning wood; as it burned, the ashes would all around the pots and bake them evenly over a few hours. Far higher temperatures were attained in special ovens, known as kilns, which would not only bake the clay and remove its plasticity, but also dissolve carbons and iron compounds. Kilns were also used for glazing, when two firings were needed. Once fired, the pots were allowed to cool slowly, and small cracks were repaired before they were ready for use.54. What does the passage mainly discuss?55. The word “meticulously” in Para.2 is closest in meaning to .56. Which of the following was a method used by some potters to give vessels a glassy finish?57. According to the passage, the advantage of kilns over open fires was that the kilns .

Most economists in the United States seem captivated by the spell of the free market. Consequently, nothing seems good or normal that does not accord with the requirements of the free market. A price that is determined by the seller or, for that matter, established by anyone other than the aggregate of consumers seems pernicious. Accordingly, it requires a major act of will to think of price-fixing (the determination of prices by the seller) as both “normal” and having a valuable economic function. In fact, price-fixing is normal in all industrialized societies because the industrial system itself provides, as an effortless consequence of its own development, the price-fixing that it requires. Modern industrial planning requires and rewards great size. Hence, a comparatively small number of large firms will be competing for the same group of consumers. That each large firm will act with consideration of its own needs and thus avoid selling its products for more than its competitors charge is commonly recognized by advocates of free-- market economic theories. But each large firm will also act with full consideration of the needs that it has in common with the other large firms competing for the same customers. Each large firm will thus avoid significant price cutting, because price cutting would be prejudicial to common interest in a stable demand for products. Most economists do not see price-fixing when it occurs because they expect it to be brought about by a number of explicit agreements among large firms; it is not.Moreover those economists who argue that allowing the free market to operate without interference is the most efficient method of establishing prices have not considered the economies of non-socialist-countries other than the United States. These economies employ intentional price fixing, usually in an overt fashion. Formal price-fixing by cartel and informal price-fixing by agreements covering the members of an industry are commonplace. Were there something peculiarly efficient about the free market and inefficient about price-fixing, the countries that have avoided the first and used the second would have suffered drastically in their economic development. There is no indication that they have.Socialist industry also works within a framework of controlled prices. In the early 1970’s the Soviet Union began to give firms and industries some of the flexibility in adjusting prices that a more informal evolution has accorded the capitalist system. Economists in the United States have hailed the change as a return to the free market. But Soviet firms are no more subject to prices established by a free market over which they exercise little influence than are capitalist firms; rather, Soviet firms have been given the power to fix prices.50. The author’s attitude toward “Most economists” in the United States (para 1) can best be described as .51. It can be inferred from the author’s argument that a price fixed by the seller “seems pernicious” (para 1) because .52. The suggestion in the text that price fixing in industrialized societies is normal arises from the author’s statement that price-fixing is .53. According to the author, price fixing in non-socialist countries is often .

暂未登录

学员用户尊享特权

老师批改作业做题助教答疑学员专用题库高频考点梳理

上一页 1 2 3 4 5 6 下一页