单选题______fire tests gold, so does adversity tests courage.

单选题The coastlines on the two sides of the Atlantic Ocean present a notable parallelism: the easternmost region of Brazil, in Pernambuco, has a convexity that corresponds almost perfectly with the concavity of the African Gulf of Guinea, while the contours of the African coastline between Rio de Oro and Liberia would, by the same approximation, match those of the Caribbean Sea. Similar correspondences are also observed in many other regions of the earth. This observation began to awaken scientific interest about sixty years ago, when Alfred Wegener, a professor at the University of Hamburg, used it as a basis for formulating a revolutionary theory in geological science. According to Wegener, there was originally only one continent or landmass, which he called Pangea. Inasmuch as continental masses are lighter than tile base on which they rest, he reasoned, they must float on the substratum of igneous rock, known as sima, as ice floes float on the sea. Then why, he asked, might continents not be subject to drifting? The rotation of the globe and other forces, he thought, had caused the cracking and, finally, the breaking apart of the original Pangea, along an extensive line represented today by the longitudinal submerged mountain range in the center of the Atlantic. While Africa seems to have remained static, the Americas apparently drifted toward the west until they reached their present position after more than 100 million years. Although the phenomenon seems fantastic, accustomed as we are to the concept of the rigidity and immobility of the continents, on the basis of the distance that separates them it is possible to calculate that the continental drift would have been no greater than two inches per year.

单选题Planning our vocation we must take the frequent ______ of the weather into consideration.(2008年四川大学考博试题)

单选题When the engine would not start, the mechanic inspected all the parts to find what was at ______. A. wrong B. trouble C. fault D. difficulty

单选题What does the example "committed perjury" illustrate?

单选题______ individuals as take up this role often find life frustrating.

单选题We shall probably never be able to ______ the exact nature of these sub-atomic particles. A. assert B. impart C. ascertain D. notify

单选题 Humans not only love eating ice cream, they enjoy{{U}} (21) {{/U}}it to their pets. Market studies show that two thirds of all dog owners give ice cream to the dogs.{{U}} (22) {{/U}}, says William Tyznik, an expert in animal nutrition at Ohio State University, "ice cream is not good for dogs. It has milk sugar in it," he says, "which dogs cannot{{U}} (23) {{/U}}very well." {{U}} (24) {{/U}}by that knowledge but aware of the desire of dog owners to{{U}} (25) {{/U}}their companions, Tyznik invented a new frozen treat for dogs that, he says, is more nutritious than ice cream-and as much{{U}} (26) {{/U}}to eat. The product, called Frosty Paws, is made of a liquid by-product of cheese and milk with the sugar{{U}} (27) {{/U}}. Frosty Paws also contains refined soy flour, water, vegetable oil, vitamins and minerals. It{{U}} (28) {{/U}}Tyznik, who has also invented a horse feed (called Tizwhiz) and{{U}} (29) {{/U}}dog food (named Tizbits), three years to{{U}} (30) {{/U}}the Frosty Paws formulas, and two{{U}} (31) {{/U}}to commercialize it. After losing $25,000 trying to market the invention himself, Tyznik sold the rights to Associated Ice Cream of Westerville, Ohio, which makes the product and{{U}} (32) {{/U}}it in cups. Tyznik claims that Frosty Paws has been tested{{U}} (33) {{/U}}and that "dogs love it". Of 1,400 dogs that have been{{U}} (34) {{/U}}the product, he says, 89 percent took it on the first{{U}} (35) {{/U}}. Three out of four{{U}} (36) {{/U}}it to Milk-Bone or sausages. The product, which will be{{U}} (37) {{/U}}in the ice-cream section of supermarkets, comes in{{U}} (38) {{/U}}of three or four cups, costing about $1.79. What would happen{{U}} (39) {{/U}}a human should mistake Frosty Paws for real ice cream? "Nothing," says Tyznik. "It's{{U}} (40) {{/U}}, but frankly, it won't taste very good. "

单选题The bishop preached a farewell sermon to a ______ that filled the church to over- flowing.

单选题There is currently abroad a new wave of appreciation for breadth of knowledge. Curricula at universities and colleges and programs in federal agencies extol(赞扬)the virtues of a broad education. For scientists who work in specialized jobs, it is a pleasure to escape in our spare time to read broadly in fields distant from our own. Some of us have made interdisciplinary study in our occupation, which is no surprise, because much of the intellectual action in our society today lies at the interfaces between traditional disciplines. Environmental science is a good example, because it frequently requires us to be conversant in several different sciences and even some unscientific fields. Experiencing this breadth of knowledge is stimulating, but so is delving deeply into a subject. Both are wonderful experiences that are complementary practical and aesthetic(美学的)ways. They are like viewing the marvelous sculpture of knowledge in two different ways. Look at the sculpture from one perspective and you see the piece in its entirety, how its components connect to give it form, balance, and symmetry. From another viewpoint you see its detail, depth, and mass. There is no need to choose between these two perspectives in art. To do so would subtract from the totality of the figure. So it is with science. Sometimes we gaze through a subject and are reluctant to stop for too much detail. As chemists, we are fascinated by computer sciences or molecular genetics, but not enough to become an expert. Or we may be interested in an analytical technique but not enough to stay at its cutting edge. At other times, we become immersed in the detail of a subject and see its beauty in an entirely different way than when we browse. It is as if we penetrate the surface of the sculpture and pass through the crystal structure to the molecular level where the code for the entire structure is revealed. Unfortunately, in our zeal for breadth or depth, we often feel that it is necessary to diminish the value of the other. Specialists are sometimes ridiculed with names such as "nerd" or "technocrats" , generalists are often criticized for being too "soft" or knowing too little about any one thing. Both are ludicrous(可笑的)accusations that deny a part of the reality of environmental science. Let us not be divided by our passion for depth or breadth. The beauty that awaits us on either route is too precious to stifle, too wonderful to diminish by bickering(争吵).

单选题After the violent earthquake that shook Los Angeles in 1994, earthquake scientists had good news to report；The damage and death toll could have been much worse. More than 60 people died in this earthquake. By comparison, an earthquake of similar intensity that shook America in 1988 claimed 25,000 victims. Injuries and deaths were relatively less in Los Angeles because the quake occurred at 4:31 a. m. on a holiday, when traffic was light on the city's highways. In addition, changes made to the construction codes in Los Angeles during the last 20 years have strengthened the city's buildings and highways, making them more resistant to quakes. Despite the good news, civil engineers aren't resting on their successes. Pinned to their drawing boards are blueprints for improved quake-resistant buildings. The new designs should offer even greater security to cities where earthquakes often take place. In the past, making structures quake-resistant meant firm yet flexible materials, such as steel and wood, that bend without breaking. Later, people tried to lift a building off its foundation, and insert rubber and steel between the building and its foundation to reduce the impact of ground vibrations. The most recent designs give buildings brains as well as concrete and steel supports, called smart buildings, the structures respond like living organisms to an earthquake's vibrations. When the ground shakes and the building tips forward, the computer would force the building to shift in the opposite direction. The new smart structures could be very expensive to build. However, they would save many lives and would be less likely to be damaged during earthquakes.

单选题

单选题Humanity uses a little less than half the water available worldwide. Yet occurrences of shortages and droughts are causing famine and distress in some areas, and industrial and agricultural by-products are polluting water supplies. Since the world"s population is expected to double in the next 50 years, many experts think we are on the edge of a widespread water crisis. But that doesn"t have to be the outcome. Water shortages do not have to trouble the world—if we start valuing water more than we have in the past. Just as we began to appreciate petroleum more after the 1970s oil crises, today we must start looking at water from a fresh economic perspective. We can no longer afford to consider water a virtually free resource of which we can use as much as we like in any way we want. Instead, for all uses except the domestic demand of the poor, governments should price water to reflect its actual value. This means charging a fee for the water itself as well as for the supply costs. Governments should also protect this resource by providing water in more economically and environmentally sound ways. For example, often the cheapest way to provide irrigation water in the dry tropics is through small-scale projects, such as gathering rainfall in depressions and pumping it to nearby cropland. No matter what steps governments take to provide water more efficiently, they must change their institutional and legal approaches to water use. Rather than spread control among hundreds or even thousands of local, regional, and national agencies that watch various aspects of water use, countries should set up central authorities to coordinate water policy.

单选题Petrazzini's main concern is not so much cultural homogenization associated with the spread of the Internet, but an exacerbation of the gap between young and old and between spread of the Internet

单选题The ongoing negotiation relied on unorthodox channels, avoiding the dull State Department, which he Udisdained/U.

单选题The question of whether war is inevitable is one which has concerned many of the world's great writers. Before considering this question, it will be useful to introduce some related concepts. Conflict, defined as opposition among social entities (实体) directed against one another, is distinguished from competition, defined as opposition among social entities independently striving for something which is in inadequate supply. Competitors may not be aware of one another, while the parties to a conflict are. Conflict and competition are both categories of opposition, which has been defined as a process by which soical entities function in the disservice of one another. Opposition is thus contrasted with cooperation, the process by which social entities function in the disservice of one another. These definitions are necessary because it is important to emphasize that competition between individuals or groups is inevitable in a world of limited resources, but conflict is not. Conflict, nevertheless, is very likely to occur, and is probably an essential and desirable element of human societies. Many authors have argued for the inevitability of war from the premise that in the struggle for existence among animal species, only the fittest survive. In general, however, this struggle in nature is competition, not conflict. Social animals, such as monkeys and cattle, fight to win or maintain leadership of the group. The struggle for existence occurs not in such fights, but in the competition for limited feeding areas and for the occupancy of areas free from meat eating animals. Those who fail in this competition starve to death or become victims to other species. This struggle for existence does not resemble human war, but rather the competition of individuals for jobs, markets, and materials. The essence of the struggle is the competition for the necessities of life that are insufficient to satisfy all. Among nations there is competition in developing resources, trades, skills, and a satisfactory way of life. The successful nations grow and prosper, the unsuccessful decline. While it is true that this competition may include efforts to expand territory at the expense of others, and thus lead to conflict, it cannot be said that, war-like conflict among nations is inevitable, although competition is.

单选题The child in the nursery ______.

单选题Colleges in the (newly formed) United Sates, (in recovering), from the adverse effects of the American Revolution, inaugurated (a broad curriculum) (in response of) social demands.A. newly formedB. in recoveringC. a broad curriculumD. in response of

单选题Twenty pounds______ enough for such a poor family to spend for a month.