| 托福考试易错题（2019/5/5） |
| 第1题： A、Two different types of bones in the human body. B．How bones help the body move. C．How bones continuously repair themselves. D．The chemical composition of human bones. |
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| 第2题：Perhaps one of the most dramatic and important changes that took place in theMesozoic era occurred late in that era, among the small organisms that populate theuppermost, sunlit portion of the oceans--the plankton. The term "plankton" is a broadone, designating all of the small plants and animals that float about or weakly propel(5) themselves through the se A、In the late stages of the Mesozoic er A、during theCretaceousperiod, there was a great expansion of plankton that precipitated skeletons or shellscomposed of two types of mineral: silica and calcium carbonate. This developmentradically changed the types of sediments that accumulated on the seafloor, because,while the organic parts of the plankton decayed after the organisms died, their mineralized(10)skeletons often survived and sank to the bottom. For the first time in theEarth’’s longhistory, very large quantities of silica skeletons, which would eventually harden into rock,began to pile up in parts of the deep se A、Thick deposits of calcareous ooze made up ofthe tiny remains of the calcium carbonate-secreting plankton also accumulated as neverbefore. The famous white chalk cliffs ofDover, in the southeast ofEngland, are just one(15)example of the huge quantities of such material that amassed during theCretaceousperiod; there are many more. Just why the calcareous plankton were so prolific duringthe latter part of theCretaceous period is not fully understooD、Such massive amountsof chalky sediments have never since been deposited over a comparable period of time.The high biological productivity of theCretaceous oceans also led to ideal conditions(20)for oil accumulation. Oil is formed when organic material trapped in sediments is slowlyburied and subjected to increased temperatures and pressures, transforming it intopetroleum. Sediments rich in organic material accumulated along the margins of theTethys Seaway, the tropical east-west ocean that formed whenEarth’’s single landmass(known as Pangaea) split apart during the Mesozoic er A、Many of today’’s important oil(25)fields are found in those sediments--in Russia, the MiddleEast, the Gulf of Mexico, andin the states of Texas and Louisiana in the United States.The word "accumulated" in line 8 is closest in meaning to A、depended B．matured C．dissolved D．collected |
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| 第3题：1 The Pacific Northwest coast of NorthAmerica is a temperate rain forest, where trees like the red cedar grow straight trunks more than two meters thick at the base and sixty meters high. Western red cedar is often called the canoe cedar because it supplied the native people of the region with the raw material for their seagoing dugout canoes. These extraordinary crafts, as large as twenty meters in length, were fashioned from a single tree trunk and carried as many as forty people on fishing and whaling expeditions into the open ocean. 2 The Haida people from the QueenCharlotte Islands offBritishColumbia were noted for their skill in canoe building.After felling a giant tree with controlled burning, the canoe makers split the log into lengthwise sections with stone wedges. They burned away some of the heartwood, leaving a rough but strong cedar shell. They then carved away wood from the inside, keeping the sections below the waterline thickest and heaviest to help keep the canoe upright in stormy seas. To further enhance the canoe’s stability, they filled the hull with water and heated it to boiling by dropping in hot stones. This rendered the wood temporarily flexible, so the sides of the hull could be forced apart and held with sturdy wooden thwarts, which served as both cross braces and seats. The canoes were often painted with elaborate designs of cultural significance to the tribe. 3The Haida raised canoe building to a high art, designing boats of such beauty and utility that neighboring tribes were willing to exchange quantities of hides, meats, and oils for a Haida canoe. These graceful vessels became the tribe’s chief item of export. In their swift and staunch canoes, the first people of the Northwest were able to take full advantage of the riches provided by the se A、With harpoons of yew wood, baited hooks of red cedar, and lines of twisted and braided bark fibers, they fished for cod, sturgeon, and halibut, and hunted whales, seals, and sea otters. The word fashioned in paragraph 1 is closest in meaning to A、thrown B．lowered C．made D．decorated |
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| 第4题：GENERAL SYSTEMS THEORY 1The Greek word "systema" means union, and scientists use the word "system" to describe a collection of several components that are linked to one another by functional relationships.Everything outside the system is known as the surroundings. Most scientific literature is a description of the components of a system, their relationships with one another, and their relationships with other systems.Although each science has its own systems with their own subject matter and networks of relationships, the formal characteristics of systems are similar for all sciences. The scientific discipline called general systems theory formulates principles that are valid for systems in general, no matter the elements involved and the relations or forces among them. 2Systems can be divided into two types: closed systems and open systems.A、closed system receives no supply of energy from outside and transfers no energy outwards.An open system receives energy from its surroundings and transfers it out again. 3 A、closed system is isolated fiom its surroundings. The energy supply of a closed system is limited and is progressively used up by the processes operating within the system. The ability of the system to function decreases as the available energy is exhausteD、Without any additional energy supplied from the outside, the system’s processes stop altogether and no further change is possible in the system.A、mill wheel supplied with water from a non-refillable container is a closed system. Once the container of water is empty, the wheel no longer turns because there is no water to turn it. In a truly closed system, the water would have to be collected below the mill wheel in a second container to ensure that the system did not supply any energy to the outside. 4Some scientists argue that there are few truly closed systems in nature, and many define closed systems more broadly as those allowing energy but not mass to cross the system boundary.By this definition, theEarth system as a whole is a closed system. The boundary of theEarth system is the outer edge of the atmosphere, and except for the occasional meteorite, virtually no mass is exchanged between theEarth system and the rest of the universe. However, energy in the form of solar radiation passes from the sun, through the atmosphere to theEarth’s surface, which in turn radiates energy back out to space across the system boundary. Hence, energy passes across theEarth’s system boundary, but mass does not, making it a closed system. 5In an open system, energy and mass can be transferred between the system and its surroundings. Living organisms are open systems. They absorb light energy or chemical energy in the form of organic molecules and release heat and metabolic waste products, such as carbon dioxide, to the surroundings. Generally, relationships exist between the components of a system and its surroundings, that is, other systems.Each open system is part of a larger system that receives and gives off energy. In an open system, the energy is continually resupplied from sources outside the system. In the example of the mill wheel, if the non-refillable water container is replaced by a reservoir fed continuously by a stream, it becomes an open system because the energy supply is renewed from the outside. 6The natural environment is made up of open systems. These can behave as closed systems temporarily if the energy supply is halted for a perioD、If, for example, the stream to the reservoir supplying the mill dries up for a long period, the energy consumption of the mill wheel cannot be balanced by new energy supply. The water in the reservoir is used up, and if the dry period is long enough, the mill wheel stops turning.Eventually, the stream may flow again, filling the reservoir and turning the mill wheel again. This occurs because the stream-reservoir-mill system is itself a part of theEarth’s much l |
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| 第5题： Clipper Ships Clipper ships are small, lightweight vessels with three masts that boast a massive array of sails which allow them to move extremely quickly. The name "clipper" is thought to come from the fact that the bow of such a ship seems to cut through water as it advances, something also true of older types of ship.Certainly, people were using the expression "to go at a good clip" to mean "to travel quickly" long before the advent of the clipper ship, so the explanation seems to make sense. In fact, it is difficult to date the emergence of the first true clipper, since the word was liberally applied to several speedy ships from the early 19th century that did not possess the technical specifications to qualify as clippers under the later definition of the term. What is known, however, is that by the 1840s, several shipyards were engaged in building vessels that were recognizably clipper ships. The great advantage of the clipper ship was its speeD、A、decently built clipper ship could routinely cover 250 miles per day, and with good winds, would often travel much faster, in some cases surpassing 400 miles per day. This made the clipper ideal for transporting people from one place to another, since prolonged sea voyages at that time were unpleasant and risky. The clippers were also used to transport freight, but in a more limited fashion, since clippers had considerably less cargo space than ordinary freighters of the time. ■ A、This meant that it was often cheaper to transport durable goods, such as furniture and jewelry, on regular ships that could carry a greater amount of cargo, even if it took longer for that cargo to reach its destination. ■ B、However, for perishable goods, such as spices and teas which would lose their potency over time, clippers proved an immensely profitable method of transport. ■ C、Clippers were also pressed into service in situations where time was viewed as more valuable than money. This was the case at the time of theCalifornia gold rush, when gold-crazed individuals were determined to be the first to reach what they hoped would be prime prospecting locations. ■ D、 The clipper ship was also used for less respectable activities.Because its great speed meant that it could outrun or overtake virtually any other type of seafaring vessel known at the time, clippers became the ships of choice for pirates and smugglers. Pirates would use clippers to chase down slower, heavier freighters, then board their victims, transfer the most valuable pieces of cargo to the clipper, and make a speedy getaway before the authorities could get there. Smugglers could more easily conceal small clippers from prying eyes than they could large sloops, and if discovered, they had a much greater chance of successfully fleeing pursuit. This in turn forced coastal and military authorities to make use of clipper ships as well, simply to keep up with the criminal element.As a result, clippers also became favorites of maritime authorities and privateers. The term "privateers" refers to those who crewed ships that were legally entitled by their governments to attack vessels in the service of foreign powers with whom those governments were at war. Unfortunately, privateers operated essentially unsupervised, and it was not uncommon for clippers initially commissioned to guard the seas to turn pirate if theCrew saw an opportunity for a quick profit. The era of the clipper was fairly short-liveD、Clippers began being built just before the advent of steam-powered boats. These steam-powered boats quickly replaced clippers as the vessels of choice for traders, not because they were faster, since they initially weren’t, but because they were much more reliable.A、clipper, fast as it was, could only make good time with the wind behind it. Headwinds would slow it considerably, and no wind at all would leave it helplessly adrift.A、steam boat would often t |
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