托福TPO综合写作练习
TOEFL综合写作TPO50
TOEFL综合写作TPO50TOEFL iBTIntegrated WritingTPO 50Reading:Scientists are considering the possibility of sending humans to Mars in the coming decades. Although there have been successful manned missions to the Moon in the 1960s and 1970s, Mars is 150 times further away from Earth than the Moon is. Thus the project of sending humans to Mars would require solving an array of problems the Moon missions did not have to face.One problem is that a round-trip to Mars and back is likely to take at least two years. The trip to the Moon lasted only a few days, and it was easy to bring enough supplies of food, water, and oxygen; but the cargo capacity of space vehicles is too limited to put on board the food, water, and oxygen required by a crew for a period of two years. Without those essentials, though, a Mars mission is impossible.A second problem is that astronauts on the Mars mission would be in the zero-gravity environment of space for many months at a time. Spending a long time in the zero-gravity environment has negative effects on the human body, such as decreased muscle mass and lower bone density. Over the course of a two-year mission, the effects would be so severe, they would make it impossible for humans to make the trip without experiencing grave medical problems.Finally, astronauts on a mission to Mars would be exposed to dangerous levels of space radiation, much of which comes in the form of charged particles emitted by the Sun. Earth's magneticfield, which normally protects us from dangerous solar radiation, would not be able to protect a spaceship traveling in interplanetary space. Constructing a shield that would protect the whole spaceship from space radiation is at present impossible because it would add too much weight to the ship.Lecture:A trip to mars would definitely be challenging but scientists have proposed solutions to the problems the reading selection discusses.First of all, food, water and oxygen. Well astronauts can use hydroponics. Hydroponics is a technique for growing plants with their roots in water rather than in soil. It requires relatively little space. Using hydroponics, the astronauts should be able to cultivate food crops in the spacecraft. In addition, the hydroponic will grow plants with recycle waste water and release it as clean water vapor, which can be collected as drinking water. And of course, all plants absorb carbon dioxide and release oxygen. So thanks to hydroponics the astronauts will also have fresh air to breathe.Second, the effects of zero gravity. Over the last few decades, we have launched several space stations orbiting the earth. And a number of astronauts have spent many months on them in a zero gravity environment. These astronauts have learned to use several techniques to safely manage the effects of zero gravity. For example, regular exercise prevents the decrease in muscle mass. Likewise, taking vitamins and minerals like calcium slows down the decrease in astronauts’ bone density.Third, solar radiation. Astronauts traveling to Mars will be exposed to some solar radiation but this radiation will not be at dangerous levels all the time. The sun only releases dangerousamounts of radiation occasionally, during periods when it is particularly active. In order to avoid this threat, the spacecraft could be equipped with special instruments that monitor solar radiation and with a small shelter that shield against radiation but doesn’t add much weight to the ship. Most of the time, the astronauts will go about their normal business in unshielded areas of the spacecraft. But when their instruments detect increased radiation, they could stay in the small shielded area until the danger has passed.Essay Example by Garlic:In the reading passage, the author holds a negative attitude towards space travel to Mars due to three major challenges. However, in the lecture, the professor provides countermeasure to these problems and deems this journey realistic.First, the author says that astronauts do not have enough food, water or oxygen to survive in the journey because of the long distance from Earth to Mars as well as the limited capacity of spaceships. Nevertheless, the professor advocates hydroponics, which strategy grows vegetation for food, recycles waste water from plants’water vapor and generates oxygen in the meanwhile.Second, the author asserts that the zero-gravity environment will put astronauts’health at risk, in other words, people will lose muscle and bone mass. On the contrary, the professor points out that astronauts can employ several technologies to handle this: They can do more physical exercise to maintain muscle strength and take vitamin and calcium pills to keep bone mass/density.Lastly, according to the author, solar radiation also imposes a grave threat to astronauts’ health since a spaceship, when traveling in the universe, is not protected by Earth’s magneticfield. To render disproof, the professor contends that solar radiation is dangerous only when the sun is hyperactive in rare occasions. Therefore, astronauts can be well protected if a solar monitor and a light and independent vault/shielding capsule are installed into the spaceship.(233 words)。
托福TPO52综合写作题目及范文(附解析)
托福TPO52综合写作题目及范文（附解析）托福TPO52综合写作题目及范文(附解析)TPO52综合写作的阅读要点内容为蔗糖可能带来许多健康风险，当作为糖的替代品。
今天给大家带来写作思路解析及范文，希望对大家有帮助。
托福TPO52综合写作题目听力文本：M: Now listen to part of a lecture on the topic you just read about:M: Many studies have found sucralose to be perfectly safe for people to consume. And it is useful for people who are trying to lose weight. The reading’s arguments against using sucralose can all be challenged.First, about sucralose affecting the thymus. If you look closely at the studies of sucralose consumption, there were no effects on the rats at all until they were eating extremely large quantities of sucralose. In order for a human to eat the equivalent amounts that affected the rats being studied, a human would have to consume about 4000 packets of sucralose per day for a month.Second, sure, some organochlorines are toxic. If they are consumed, they are digested and stored in fat tissue, and they continue to build up in the fat tissues till they reach toxic levels. But studies show sucralose is a bit different from the other organochlorines. Sucralose is not absorbed by the digestive system very well and so it does not accumulate in the body’s fat tissue. Since sucralose is not absorbed well by the digestive system and doesn’t build up to dangerous leve ls in fat tissue, it is unlikely to have the toxic effect that the otherorganochlorines do.Finally, there is the argument that many people who use artificial sweeteners in their drinks end up eating lots of real sugar in food like cake, and so they negate the benefits of using the sweetener. Well, that argument may hold true for many artificial sweeteners but sucralose has a unique property that makes it different. Most artificial sweeteners breakdown if they are heated too much, but sucralose does not break down when heated. That means that unlike other sweeteners, sucralose can be used to bake things, like cakes and cookies, for example. People craving something sweet can turn to cakes or cookies baked with sucralose, which helps them keep their diets on track.M: Summarize the points made in the lecture, being sure to explain how they challenge the specific points made in the reading passage.阅读文本：ReadingSucralose is an artificial sweetener that is used in place of natural sugar. Many people use sucralose as a substitute for sugar to control their weight. However, there may be several health risks associated with sucralose. Also, it is not clear whether sucralose actually helps people lose weight.First, researchers in Australia did studies on rats and discovered that sucralose consumption caused shrinking of the thymus in rats. The thymus is an organ that is crucial to maintaining a healthy immune system; in humans it is particularly active in childhood. If sucralose has similar effects on humans, then long-term use of sucralose could cause harm to the immune system, especially in children.Second, sucralose is created by replacing some of the atoms in natural sugar molecules with chlorine. This means sucralose belongs to a group of chemicals called organochlorines, which is another cause for concern. Organochlorines are known to be toxic to plants and animals, including humans. Some organochlorines are even used as pesticides. Sucralose is chemically similar to these toxic chemicals, so there may be a risk of poisoning if sucralose builds up in human body tissue (in fat tissue, for example).Third, substituting artificial sweeteners for real sugar in coffee, tea, and soft drinks often does not help people lose weight, since it reinforces the habit of enjoying sweet food. When people use artificial sweeteners in their drinks, their appetite for sugar remains strong, and they satisfy their sweetness cravings by eating greater portions of foods containing real sugar, such as cakes or cookies. Such eating habits can prevent them from achieving their goal of losing weight.Summarize the points made in the lecture, being sure to explain how theysupport/contradict specific points made in the reading passage.答题思路：1. 阅读要点概括：Main point: Sucralose may bring about many health risks when used as a substitute for sugar.Sub point 1: Sucralose may cause harm to the immune system.Sub point 2: There may be a risk of poisoning if sucralose builds up in human body tissue.Sub point 3: Substituting artificial sweeteners for real sugar does not help people lose weight.2. 听力要点概括：Main point: Sucralose is perfectly safe for people to consume.Sub point 1: It requires a consumption of extremely large quantities of sucralose to affect the thymus.Sub point 2: Sucralose does not accumulate in the body’s fat tissue so that it is unlikely to have the toxic effect.Sub point 3: People can use sucralose to replace sweet while keep their diets on track.范文：The sp eaker rebuts the reading’s arguments by debunking the exaggerated tested side effect on the human body, the hasty generalization that sucralose is proven toxic, and unwarranted claims that Sucralose can increase one’s sugar intake.The speaker begins by stating that Sucralose does affect the thymus, but only when the individual consumes a very large quantity of it, over 4000 packets per day. Despite the claim from the reading that sucralose might exert similar detrimental effects on a human thymus given the conclusive side effect has been witnessed in rats, the professor argues Sucralose can only pose a threat to one’s health under mass usage.Contrary to the belief in the passage that it belongs to a group of toxic chemicals called Organochlorines, Sucralose has been shown to act differently than traditional Organochlorines. The professor argues that people have a hard time fully digesting it and it does not build up in the body, therefore it is much less toxic. This directly challenges the fundamental theory in reading.Lastly, the professor casts doubt on the validity of the assumption that sucralose can encourage binge intakes of sweet food. The reading reasons that sucralose can build a growing reliance on sweetness, thus further d amaging one’s health.However, the speaker maintains that the very nature of Sucralose can endure a high heating temperature, thus serving as a perfect candidate to replace artificial sweeteners. In that sense any unfair concern over Sucralose being a gateway sugar inducer would be groundless.。
TPO 24 托福综合写作范文
TPO 24综合写作
阅读：恐龙化石里面含有actual tissue
听力：
阅读1：科学家发现了通道分支，在里面发现了soft and flexible organic substance, 证明actual blood vessel。
听力1：not blood vessel
有机体死了之后，细菌colonize骨骼，留下痕迹，细菌的遗留物
阅读2：sphere里面含有铁，可能是the remains of 红细胞
听力2：在其他动物化石里面也发现了，这些原始动物没有红细胞，不能证明恐龙化石里面含有红细胞
有其他来源，reddish minerals
阅读3：发现了骨中含有collagen，他是living bone tissue 的重要组成部分
听力3：不能存活太长时间：a hundred thousand years. 恐龙已经死亡超过70 million years ，发现的蛋白质不是恐龙
可能有其他来源：研究人员在处理骨头的时候留下的。
tpo 综合写作文本答案
TPO 24Animal fossils usually provide very little opportunity to study the actual animal tissues because in fossils the animals' living tissues have been largely replaced by minerals. Thus, scientists were very excited recently when it appeared that a 70-million-year-old fossil of Tyrannosaurus rex (T. rex), a dinosaur, might still contain remains of the actual tissues of the animal. The discovery was made when researchers deliberately broke open the T. rex's leg bone, thereby exposing its insides to reveal materials that seem to be remains of blood vessels, red blood cells, and collagen matrix.First, the breaking of the fossilized leg bone revealed many small branching channels inside, which probably correspond to hollows in the bones where blood vessels were once located. The exciting finding was the presence of a soft, flexible organic substance inside the channels. This soft substance may very well represent the remains of the actual blood vessels of T. Rex.Second, microscopic examination of the various parts of the inner bone revealed the presence of spheres that could be the remains of red blood cells. Tests showed that the spheres contained iron - a material vital to the role of red blood cells in transporting oxygen to tissues. Moreover, the spheres had dark red centers (substances with iron tend to be reddish in color) and were also about the size of red blood cells.Third, scientists performed a test on the dinosaur leg bone that showed that it contained collagen. Collagen is a fibrous protein that is a main component of living bone tissue, in which it forms a so-called collagen matrix. Collagen (or its chemical derivatives) is exactly the kind of biochemical material that one would expect to find in association with bone tissue.As much as we would like to have the remains of actual dinosaur tissue, there are sound reasons for being skeptical of the identifications made in the reading.First, the soft, flexible substance inside the bone channels isn't necessarily the remains of blood vessels. It is much more likely to be something else. Like what? You might say. Well, long after an organism is died, bacteria sometimes colonize hollows, empty areas in bones, like the channels that once held blood vessels. When bacteria lived inside bones, they often leave behind traces of organic material. What the researchers in the reading are identifying as blood vessels might just be traces of soft and moist residue left by bacteria colonies.All right. What about the iron-filled spheres? Well, the problem is that scientists found identical reddish spheres in fossils of other animals found in the same place. That includes fossils of primitive animals that did not have any red blood cells when they were alive. Clearly, if these spheres appear in organisms that did not have any red blood cells, then the spheres cannot be the remains of red blood cells. The spheres probably have a very different origin. They are probably just pieces of reddish mineral.Third, the collagen. The problem is that we have never found collagen in animal remains that are older than one hundred thousand years. Collagen probably cannot last longer than that. Finding collagen from an animal that lived seventy million years ago would really contradict our ideas about how long collagen can last. It is just too improbable. The most likely explanation for the presence of collagen is that it doesn't come from the T.rex, but from another much more recent source. For example, human skin contains collagen, so the collagen may have come from the skin of the researchers who are handling the bone.In the reading passage, it talks about the fossils related to animal tissues, however, the professor holds different ideas.To begin with, in the reading material, we learn that the lots of tiny branching channels are found inside of the leg bone fossil. The reading material argues that soft tissue is expected to be found in the channels. However, the professor thinks that the channels are more likely to be left by bacteria. In addition, in the reading passage, it talks about that spheres are found in inner bone and red blood cells can be remained. And in the reading passage, it gives evidence that the sphere have red centers. However the professor indicates that there is no evidence show that creature at that time had red cells and the red centers should be something else.As a final point, in the reading passage, it talks about that collagen is found on the leg bone. Collagen is actually a biochemical material, which is expected to be an association with bone tissue.However, the professor says that collagen is not likely to live as long as 7 million year. It may be some recent material. For instant, it may be from the hand skin of the researchers.In conclusion the professor does not agree with the reading passage.TPO 25In 1938 an archaeologist in Iraq acquired a set of clay jars that had been excavated two years earlier by villagers constructing a railroad line. The vessel was about 2,200 years old. Each clay jay contained a copper cylinder surrounding an iron rod. The archaeologist proposed that vessel were ancient electric batteries and even demonstrated that they can produce a small electric current when filled with some liquids. However, it is not likely that the vessels were actually used as electric batteries in ancient times.First of all, if the vessels were used as batteries, they would probably have been attached to some electricity conductors such as metal wires. But there is no evidence that any metal wires were located near the vessels. All that has been excavated are the vessels themselves.Second, the copper cylinders inside the jars look exactly like copper cylinders discovered in the ruins of Seleucia, an ancient city located nearby. We know that the copper cylinders from Seleucia were used for holding scrolls of sacred texts, not for generating electricity. Since the cylinders found with the jars have the same shape, it is very likely they were used for holding scrolls as well. That no scrolls were found inside the jars can be explained by the fact that the scrolls simply disintegrated over the centuries.Finally, what could ancient people have done with the electricity that the vessels were supposed to have generated? They had no devices that replied on electricity. As batteries, the vessels would have been completely useless to them.Your reading says that these vessels were not used as batteries in ancient times, but the arguments used in the reading are not convincing. The battery explanation could very well be correct.First, about the absence of wires or other conductors, Remember, vessels were discovered by local people, not archaeologists. These people might have found other material located near the jars. But since they were not trained archaeologists, they may not have recognized the importance of that material. So materials serving as wires or conductors might have been overlooked as uninteresting or even thrown away. We’ll never know.Second, it is true that the copper cylinders in the vessels are similar to cylinders used to hold scrolls, but that does not really prove anything. It’s possible that the copper cylinders were originally designed to preserve scrolls. And that some ancient inventor later discovered that if you use them together with iron rods and some liquid in a clay vessel, they will produce electricity. That’s how the first ancient battery could have been born. In other words, the copper cylinders could have been originally used for one purpose, but then adapted for another purpose.Finally, there’s the question of the possible uses of the battery in the ancient world. Well, the battery could produce a mild shock or tingling sensation when someone touched it. This could very well have been interpreted as evidence of some invisible power. You can easily see how people could convince others that they had magical powers through the use of the battery. Also, the battery could have been used for healing. Modern medicine uses mild electric current to stimulate muscles and relieve aches and pains. Ancient doctors may have used the batteries for the same purpose.In the reading material, the author states that the vessels found in Iraq in 1938 were not actually used as electric batteries in ancient times. However in the listening material, the professor refutes that the argument is unconvincing as it was used as batteries.First, according to the reading passage, the author suggests that if they were used as batteries, they would have been attached to some electricity conductors. However in the listening, the professor claims that we should remember that the discovery was made by local people along with some other materials. As they were not trained as archaeologist, they could not recognize the importance of some certain excavations.Perhaps they were overlook as something uninterested and then thrown away. Second, the author in the reading material mentions that the vessels were likely used for holding scrolls. Unfortunately the professor argues that it could not prove anything. It is possible that the vessels may be originally designed to scrolls. However ancient inventor then discovered that if the vessels were used with iron rod and some liquid, it could generate the electricity. So the copper cylinders may be originally used for one purpose but adapted for another purpose.Finally, the author of the reading passage asserts that the vessels would have been completely useless to ancient people as they had no devices that replied on electricity. In the contrary in obviously contradicts with the listening passage in which the professor contends that the battery could generate some mild shock and this also interprets evidence of some invisible power that how people convince others they had the magic power. Also it could be used for healing. In modern society doctors would use batteries to stimulate muscles and release pains. In ancient times people could also do that.In conclusion, according to the listening material, the argument that the vessels could not be used as batteries is unwarranted.TPO 26The zebra mussel, a freshwater shellfish native to Eastern Europe, has long been spreading out from its original habitats and has now reached parts of North America. There are reasons to believe that this invasion cannot be stopped and that it poses a serious threat to freshwater fish populations in all of North America.First, the history of the zebra mussel's spread suggests that the invasion might be unstoppable. It is a prime example of an invasion made possible by human transportation. From the zebra mussel’s original habitats in Eastern Europe, ships helped spread it out along new canals built to connect Europe’s waterways. The mussel can attach itself to a ship’ s bottom or can survive in the water—called "ballast water"—that the ship needs to take on to properly balance its cargo. By the early nineteenth century, the mussel had spread to the whole of Europe. It was later carried to the east coast of North America in the ballast water of ships traveling from Europe. The way ships have spread the zebra mussel in the past strongly suggests that the species will soon colonize all of North America.Moreover, once zebra mussels are carried to a new habitat, they can dominate it. They are a hardy species that does well under a variety of conditions, and they have a high rate of reproduction. Most important, however, zebra mussels often have no predators in their new habitats, and species without natural predators are likely to dominate their habitats.Finally, zebra mussels are likely to cause a decline in the overall fish population in habitats where they become dominant. The mussels are plankton eaters, which means that they compete for food with many freshwater fish species.Contrary to what you just read, there are ways to control the zebra mussel's spread. What's more, it is not so clear that the mussel is a serious threat to fish populations.True, the spread of zebra mussels couldn't be controlled in the past, but that's because people didn't have enough knowledge. In fact, there are effective ways to stop ships from carrying the mussels to new locations. Here's an example. The way zebra mussels usually travel across the ocean is that a ship takes on some fresh "ballast water" in Europe and then empties that water into American waterways when it arrives. Full of zebra mussels, but the ship can be required to empty out the freshwater and refill with ocean water while still out in the ocean. Salt water will kill the mussels.Second, it's true that zebra mussels often don't have predators in their new habitats, but that's only in the beginning. What's been happening in Europe is that local aquatic birds sooner or later notice there's a new food source around and change their habits to exploit it. They switch from whatever they were eating before to eating zebra mussels. And birds can eat a lot of mussels. So zebra mussels aren't so likely to dominate their new habitats after all.Finally, even in habitats where zebra mussels become dominant, is the overall fish population likely to decrease. It's true that zebra mussels may have a negative impact on fish that eat plankton. But on other fish, they can have a positive impact. For example, the mussels generate nutrients that are eaten by fish that feed near the bottom of the lake or river. So bottom-feeding fish populations may increase, even if plankton-eating fish population decrease.Contrary to what is argued in the passage, the lecture illustrates how zebra mussels are not likely to become a serious threat to freshwater fish populations in North America.First and foremost, new knowledge of the zebra mussel has shed light on new ways to prevent their invasion, even though people in the past have not been able to stop the spread of zebra mussels effectively. For instance, although a large amount of zebra mussels spread to North America by staying in the ballast water of a ship, people can now get rid of them before the ship gets to the shore – if the ballast water is emptied halfway of the journey and refreshed with sea water, the zebra mussels can be exterminated as soon as they get exposed to salt water.Furthermore, zebra mussels are not likely to dominate a new habitat for a long period of time. The lecture agrees that zebra mussels may have no predators and reproduce rapidly in the beginning, but it would not be long before predators notice this new source of food and therefore prevent its domination.Finally, zebra mussels would not cause the decline of overall fish population. While zebra mussels would most likely cause the decline of plankton eaters, as the passage suggests, they would also provide nutrients for bottom-feeding fish and eventually cause the population of those fish to increase.TPO 33Carved stone balls are a curious type of artifact found at a number of |locations in Scotland. They date from the late Neolithic period, around 4,000 years ago. They are round in shape; they were carved from several types of stone; most are about 70 mm in diameter; and many are ornamented to some degree. Archaeologists do not agree about their purpose and meaning, but there are several theories.One theory is that the carved stone balls were weapons used in hunting or fighting. Some of the stone balls have been found with holes in them, and many have grooves on the surface. It is possible that a cord was strung through the holes or laid in the grooves around the ball. Holding the stone balls at the end of the cord would have allowed a person to swing it around or throw it.A second theory is that the carved stone balls were used as part of a primitive system of weights and measures. The fact that they are so nearly uniform in size -at 70 mm in diameter-suggests that the balls were interchangeable and represented some standard unit of measure. They could have been used as standard weights to measure quantities of grain or other food, or anything that needed to be measured by weight on a balance or scale for the purpose of trade.A third theory is that the carved stone balls served a social purpose as opposed to a practical or utilitarian one. This view is supported by the fact that many stone balls have elaborate designs. The elaborate carving suggests that the stones may have marked the important social status of their owners.None of the three theories presented in the reading passage are very convincing.First, the stone balls as hunting weapons, common Neolithic weapons such as arrowheads and hand axes generally show signs of wear, so we should expect that if the stone balls had been used as weapons for hunting of fighting, they too would show signs of that use. Many of the stone balls would be cracked or have pieces broken off. However, the surfaces of the balls are generally well preserved, showing little or no wear or damage.Second, the carved stone balls maybe remarkably uniform in size, but their masses vary too considerably to have been used as uniform weights. This is because the stone balls were made of different types of stone including sandstone, green stone and quartzite. Each type of stone has a different density. Some types of stone are heavier than others just as a handful of feathers weighs less than a handful of rocks. Two balls of the same size are different weights depending on the type of stone they are made of. Therefore, the balls could not have been used as a primitive weighing system.Third, it's unlikely that the main purpose of the balls was as some kind of social marker.A couple of facts are inconsistent with this theory. For one thing, while some of the balls are carved with intricate patterns, many others have markings that are extremely simple, too simple to make the balls look like status symbols. Furthermore, we know that in Neolithic Britain, when someone died, particularly a high-ranking person, they were usually buried with their possessions. However, none of the carved stone balls have been actually found in tombs or graves. That makes it unlikely that the balls were personal possessions that marked a person's status within the community.The author in the reading passage explores three major functions of the carved stone balls. However, in the lecture, the professor respectively contradicts all his assertions by using three specific points as supports.First, even though the reading passage suggests that the stone balls were weapons because of the holes and grooves on their surface, the professor argues that the stone balls didn’t show signs of use, which means they are neither cracked nor broken and thus cannot be used as weapons.Second, despite the statement in the reading passage that the stone balls were used as primitive weighing system due to their uniform size, the professor contends that their masses vary too considerably from each other. Therefore, the balls could not function as weighing system.Third, the author asserts that the stone balls served a social purpose owing to their elaborate designs while the professor proves that this claim is indefensible by pointing out that the balls were carved with not only intricate patterns but also simple ones, besides, none of the balls were found in the ancient tombs or graves. Consequently, it’s impossible that the balls were social markers.TPO 34A huge marine mammal known as Steller’s sea cow once lived in the waters around Bering Island off the coast of Siberia. It was described in 1741 by Georg W. Steller, a naturalist who was among the first European to see one. In 1768 the animal became extinct. The reasons for the extinction are not clear. Here are three theories about the main cause of the extinction.First, the sea cows may have been overhunted by groups of native Siberian people. If this theory is correct, then the sea cow population would have originally been quite large, but hundreds of years off too much hunting by the native people diminished the number of sea cows. Sea cows were a good source of food in a harsh environment, so overhunting by native people could have been the main cause of extinction.Second, the sea cow population may have become extinct because of ecosystems disturbances that caused a decline in their main source of food, kelp (a type of sea plant). Kelp populations respond negatively to a number of ecological changes. It is possible that ecological changes near Bering island some time before 1768 caused a decrease of the kelp that the sea cows depend on.Third, the main cause of extinction of the sea cows could have been European fur traders who came to the island after 1741. It is recorded that the fur traders caught the last sea cow in 1768. It thus seems reasonable to believe that hunting by European fur traders, who possessed weapons that allowed them to quickly kill a large number of the animals, was the main cause of the sea cow’s extinction.Now I want to tell you about what one company found when it decided that it would turn over some of its new projects to teams of people, and make the team responsible for planning the projects and getting the work done. After about six months, the company took a look at how well the teams performed.On virtually every team, some members got almost a “free ride”… they didn’t contribute much at all, but if their team did a good job, they nevertheless benefited from the recognition the team got. And what about group members who worked especially well and who provided a lot of insight on problems and issues? Well … the recognition for a job well done went to the group as a whole, no names were named. So it wont surprise you to learn that when the real contributors were asked how they felt about the group process, their attitude was just the opposite of what the reading predicts.Another finding was that some projects just didn’t move very quickly. Why? Because it took so long to reach consensus; it took many, many meetings to build the agreement among group members about how they would move the project along. On the other hand, there were other instances where one or two people managed to become very influential over what their group did. Sometimes when those influencers said “that will never work” about an idea the group was developing, the idea was quickly dropped instead of being further discussed. And then there was another occasion when a couple influencers convinced the group that a plan of theirs was “highly creative.” And even though some members tried to warn the rest of the group that the project was moving in directions that might not work, they were basically ignored by other group members. Can you guess the ending to this story? When the project failed, the blame was placed on all the members of the group.The writer and the professor all talk about the possible reasons for the extinction of sea cows. While the passage raises three theories about the main cause of the extinction, the lecture has differing views.According to the author, sea cows may have been over hunted by groups of native Siberian people, which could have been the main cause of the extinction. Not as the author puts it, the professor argues that over hunting for food could not be the main cause. He mentions that the sea cow was such a massive creature that could feed a small village for a month, and the population of native Siberian people was not very large. So, it was unlikely the native people hunted too much sea cow, the population of which would have originally been quite large.In the passage, it is said that a decline in their main source of food,caused by ecosystems' disturbance, may be the second explanation. On the contrary, the lecture suggests that no real evidence indicated the sea cows had little kelp to eat. The ecosystems' disturbances really happened before 1768, but it caused other part of marine creatures decreased, not sea cows' main source of food, kelp.At the points out the main cause could have been European fur traders, who were recorded catching sea cows. Quite the opposite, the speaker claims that it was not the real reason. Since the population was already small before Eropeanfur traders came to the island, there could have been something else decline a large number of the sea cows. And that is what the professor thinks the real reason of the extinction.。
托福【综合】写作TPO31题目+解析
今天，小编为托福考生们准备了托福综合写作TPO31,希望各位考生们在TPO写作真题里能够得到锻炼，祝广大托福考生能够取得理想成绩。
托福TPO31综合写作 Reading Part:A fossil skeleton of a dinosaur called Sinosauropteryx, preserved involcanic ash, was discovered in Liaoning, China, in 1996. Interestingly, thefossil included a pattern of fine lines surrounding the skeletal bones. Somepaleontologists interpret the lines as evidence that Sinosauropteryx hadfeathers. However, critics have opposed the idea that Sinosauropteryx was afeathered dinosaur, citing several reasons.First, the critics points out that the fine lines may not even representfunctional structures of a living dinosaur, but rather structures that wereformed after the animal’s death. After the animal died and was buried involcanic ash, its skin may have decomposed into fibers. The skin fibers thenbecame preserved as lines in the fossil; the lines were misinterpreted asevidence of feathers.Second, even if the fine lines are remains of real structures of aSinosauropteryx, scientists cannot tell with certainty what part of thedinosaur’s anatomy the structures were. Many dinosaurs had frills, ornamentalfan-shaped structures growing out of some parts of their bodies. Some of thecritics argue that the lines surrounding the skeleton are much more likelyto be fossilized remains of frills than remains of feathers.A third objection is based on the fact that the usual functions of feathersare to help animals fly or regulate their internal temperature. However, thestructures represented by the lines in the Sinosauropteryx fossil were mostlylocated along the backbone and the tail of the animal. This would have made the structures quite useless for flight and of very limited use in thermoregulation. This suggests that the lines do not represent feathers.托福TPO31综合写作 Listening Part:The evidence that the lines in the Sinosauropteryx fossil representfeathers is very strong. The arguments of the critics are unconvincing.First, it is unlikely that the lines are a result of the decomposition ofthe dinosaur ’s skin, because we don’t see any such decomposition in the fossils of other animals buried at the same site. In fact, the fossils of many other animals buried at the site show evidence that their functional skin structures have been beautifully preserved in volcanic ash. The well-preserved condition of the other fossils makes it likely that the Sinosauropteryx’s lines are also well-preserved functional structures, possibly feathers, and that they are not fibers caused by decomposition.Second, the idea that the lines represent frills… well, there is animportant chemical difference between feathers and frills. Feathers contain a great deal of a protein called Beta-keratin. Frills, on the other hand, do not contain beta-keratin. Our chemical analyses suggest that the Sinosauropteryx structures did contain beta-keratin. So that indicates that the structures were feathers, not frills.Third, feathers can be used for other functions than flight and thermoregulation. Think of a bird, like peacock, for example. The peacock has long, colorful feathers in its tail. And it displays its tail in order to attract a mate. That’s a distinct function of feathers called the display。
tpo41托福综合写作范文
tpo41托福综合写作范文一、阅读文章要点。
阅读文章的观点是，人类可以在火星上建立永久性的居住点，并且给出了三个理由：1. 火星的大气含有二氧化碳：这一气体可以被利用来生产燃料和氧气。
通过一些技术手段，比如将二氧化碳分解成一氧化碳和氧气，氧气可供人类呼吸，一氧化碳可作为燃料的组成部分。
这样就能解决人类在火星上生存所需要的呼吸用气和能源问题。
2. 火星的重力较低：这对于人类来说是一个优势。
低重力环境使得从火星发射宇宙飞船返回地球更加容易。
相比在地球发射火箭，需要克服巨大的重力，在火星上发射火箭所需要的燃料会少很多，从而大大降低了太空探索任务的成本和难度。
3. 火星上有冰存在：火星上的冰可以融化成水。
水是生命之源，它可以用于人类饮用、灌溉农作物等。
而且，水还可以分解成氢气和氧气，进一步为人类提供能源。
这就使得人类在火星上建立永久性居住点有了最基本的资源保障。
二、听力文章要点。
听力文章对阅读中的观点进行了反驳，理由如下：1. 二氧化碳利用困难：虽然火星大气中有二氧化碳，但是这些二氧化碳大多以固体干冰的形式存在于火星的两极。
要将其收集并转化为有用的氧气和燃料，需要复杂的设备和大量的能量投入。
以目前人类的技术水平，要将这些设备运送到火星并且维持其运行是非常困难的，所以无法像阅读中所说的那样轻易地利用二氧化碳。
2. 低重力带来健康问题：火星的低重力环境对人类健康有严重的危害。
长时间处于低重力环境下，人类的肌肉和骨骼会萎缩。
例如，宇航员在国际空间站待一段时间后返回地球时，身体就会出现各种问题。
在火星上建立永久性居住点意味着人类要长期面对这种低重力环境，这会使人类的身体状况变得非常糟糕，甚至可能威胁到生命，所以低重力并不是一个像阅读中说的那样的优势。
3. 火星上的冰难以利用：火星上的冰并不是像阅读中所说的那样容易被利用。
因为这些冰里含有很多有害物质，像高氯酸盐。
如果要将这些冰融化成水供人类使用，首先需要去除这些有害物质，而目前我们还没有一种简单有效的方法来做到这一点。
TPO30综合写作
Do you agree or disagree：Celebrities are more important to younger people than they are to older people.写作思路：题目太抽象了，结果写了两个小时。
名声对于每个人都很重要，特别是是年轻人他们可能更加在意自己的celebrity。
（1）年轻人相对于老年人有更广阔的社交，一个好的名声可以让他们交到更多的朋友，认识更多的人。
而老年人的社交相对狭窄，不需要交太多朋友。
（2）年轻人需要找工作，有一个好的名声，可以相对容易的找的工作。
而老年人找工作时，人们可能更看重他们的经验（3）外界对于一个人的信任和认可程度，老年人的认识已经比较深，了解比较多。
相对年轻人，可能大家对他们的认识不会太多，所以相对而言名誉也就更重要.When we think about the importance of celebrities for a person, we can say it's more important for a younger people to have good celebrities than older people. There are several reasons for that, such as the social relationship for young people, the younger needing to find a good job and people's cognition to them.First, younger people have wider social relationship than the elderly. Young people always have a lot of friends and they also like to make friends with other people. If a young people have a good reputation, people may like to build a relationship with him or her. For example, my friend Sally is a beautiful and hot-heart girl, she likes to help other people no matter what kind of problems they meet, so she gets a good reputation in our college. One day, one of my friends coming from another college asked me if I was acquainted with sally and he wanted to make friends with her. I was surprised since Sally was unlikely to have any interactions with him. Then I know the reason that it's the Sally's good fame making people like my friend want to make friends with her. However, the elderly have a relatively small social relationship and do not need to make many friends. Thus the celebrities to them are comparatively less important than then the younger.Besides, since young people have little working experience, their boss may value their celebrities much more. When the young people go to find some jobs, their employers know little about them. So they would prefer to ask their school teachers for advice, if the young people have left good impression in their teachers. They may have more chances to get their jobs. Even some teachers would recommend best students who have good celebrity in school to big companies. But when it comes to older people, due to their lots of working experience, their employer may concern more about if their working experience are suitable for their company not the fame. From this point of view, the celebrities to younger people are more important. Finally, because the elderly have been familiar by others, they can easily get the trust from other people, while a young people may need a good reputation to get others'trust. As we know, many old people have worked for dozens of years, their boss and coworkers already have a great acquaintance with them, what kind of character they are, what they like and dislike. So it's easier for them to get trust from those persons. But for a new young employee, many people do not know them. If they want to get same trust as the older, they need to accumulate their good fame. A good celebrity can make unfamiliar people trust young people and help them get involved in the company.In the nutshell, celebrities are of more significance for younger people and have a more impact their lives. Therefore, for younger people, celebrities are more important than the older people.。
tpo72综合写作范文(汇总3篇)_1
tpo72综合写作范文(汇总3篇) In 1990, new rules and guidelines were adopted in the United Kingdom that has changed the whole field of Archaeology in that country. The new guidelines improved the situation in all there areas discussed in the passage.First, the new guidelines state that before any construction project can start, the construction site has to be examined by archaeologists to see whether the site is of archaeological interest or value. If the site is of archaeological interest, the next step is for the builders, archaeologists and local government officials to get together and make a plan for preserving the archaeological artifacts, either by building around them or by excavating and documenting them properly before the construction is allowed to proceed.Second, an important part of the new guidelines is a rule that any archaeological work done on the construction site will be paid for by the construction company not by the government. The construction company has to pay for the initial examination of the site, and then for all the work carried out under the preservation plan. This is a whole new source of financial support. The funding from construction companies has allowed researchers to study a far greater range of archaeological sites than they could in the past.Last, the new guidelines provide a lot of paid work for archaeologists, work that didn’t exist before. Expert archaeologists are now hired at all stages of the process to examine the site for archaeological value, then to help draw up the preservation plan to do the research in a professional scientific manner and finally to process the date and write reports and articles. The increased job and career opportunities in Archaeology have increased the number of professional archaeologists in Britain, which is now the highest it’s ever been.Some people believe that educatingchildren alt**ether will benefit them. Others think intelligent children shouldbe taught separately and given special courses. Discuss both views and giveyour own opinion.写作就像盖房子一样，关键词与句式只是钢筋结构，起着框架性的作用，换句话说，光掌握关键词与句式是不够的——要想在托福独L写作中取得高分，准确的用词、过硬的语法基础都是不可或缺的，希望大家能够在平时多加积累与练习，为备战托福打下坚实的基础。
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TPO 1 (综合)（用时23:08 s）The reading passage explore the issue that four-day work week policy. The professor ‘s lecture deals with the same issue. However, he think that this policy can not benefit the companies and the employees, which contradicts what the reading states. And in the lecture, he use three specific points to supports his view.To begin with, even through the reading passage suggest that companies can through this policy to increase their profits, the professor argues in the lecture that companies would spend more under fou-day week. That is because they have to provide more training, medical insurance, work space even more computers for additional employees. Obviously, the professor’s argument disproves it’s counterpart in the reading.Moreover, despite the statement in the reading that the fou-day week policy would benefit the whole country, the speaker contends that the companies which have higher expectation would leave their employees with five-day work within four days, which would make employees more unpleasant.Finally, the writer insist that the four-day work week good for the individual employees. On the contrary, the professor casts doubt on the writer expectation again by saying that the policy would risky the employees’s job stability. In order to demonstrate his perspective, the lecture provides us with the fact that four-day work employees always be passover by promotion ,the leader appreciate the employees who have entire work week.TPO 20 （综合）(243 & on time)The reading passage explore the issue that the famous natural forest fire happened in the summer of 1988, in Yellowstone. The professor deals with the same issue. However, he think that the natural fires is creative part of the nature, which contradicts what the reading states. And in the lecture, the professor use three specific points to support his view.To begin with, even though the reading passage suggest that the fires cause damage to trees and other vegetations in the park, the professor argues in the lecture that the fires provides more opportunities for new plants to grow, especially those small trees which usually be shielded by the bigger ones, and some seeds need more heat to sprout can also get the chance to alive.Moreover, despite the statement in the reading that wild life will be affected for the distribution of food chains. The speaker contends that the fires also can create some ideal habitats for some animals like rabbits and hares and the food chain can become stronger instead of be destroyed.Finally, the writer insists that the local economy would be influenced by the fire's negative affect on the tourist attraction. On the contrary, the professor casts doubt on the writer'sopinion by saying that the fires is unusual which caused by the lack of rainfall and the strong winds , and would not happened every year because the rainfall, and the visitors can come next year or each year after the fires, which would not attack the local economy.TPO 19 （综合）(222 & have two minutes left to check)The reading passage explores the issues that the buzzing in the commercial advertisements, the speaker in the lecture deals with the same issue. However, he think that the buzzing do not misleading the public, which contradicts what the reading states. And in the lecture, the students use three specific points to support his view.To begin with, even through the reading passage states that the public should realize that the people praising the products just because they are be paid and they don’t tell the truth, the speaker argue that the buzzing is present the truly feeling of the products users who is enjoy using the products, they should to be paid to tell their experience of using. Obviously, the student's argument disprove it's counterpart in the reading.Moreover, despite the statement in the passage that the buzzers all present their private opinions, which can not represent the whole consumers. The speaker contends that the consumers can value the products by the prices and services , so is not easily to charge their final decision just by some buzzers.Finally, the writer insists that the buzzing is bad for the social relationships between people. On the contrary, the student think the reading's view is pretty stupid, because if the consumer buy and use the products, that means they trust the buzzers’experience, which is the promoting of the honesty between people.TPO 18 （综合）(227 & have one minute left to check)The reading passage explores the issue that Torreya will be died out in a short time, the professor's lecture deals with the same issue. However, she thinks that the three solutions to reserve the Torreya that illustrated in the reading passage, none of them will be success, which contradicts what the reading states. And in the lecture, she use three specific points to support her view.To begin with, even through the reading passage suggests that the Torrega can be reestablish in the location where it has set their own microclimate, the professor argues that this solution can not be work, it is because the microclimate can be changed with the large region. To be specific, the global warming can make the microclimate become more drier that the Torreya can not survived, Obviously, the professor's argument disprove its counterpart in the reading.Moreover, despite the statement in the reading that move Torreya to the further north can save them, the speaker contends that the black locust is the example to show that the migration will kill other trees and plants that living in the new conditions.Finally, the writer insists that the research center would be the best place to preserve the Torreya. On the contrary, the professor casts doubt on the writer's opinion by saying that the Torreya in the labs can not survived from losing the abilities to resist the diseases in a long term.TPO 17（综合）(221 & on time)The reading passage explores the issue that the bird’s population. The professor's lecture deals with the same issue. However, she thinks that the population of birds will not decline, which contradicts what the reading states. And the professor uses three specific points to support her view.To begin with, even though the statement of reading passage is that the expand of humans harming the habitats of birds. The professor argues that some birds' habitats is becoming better and bigger during the urbanization. It is according to the fact that the region of pigeons and sea gulls is in rising, which indicates that some birds’s habitats are shrinking, but the habitats of other birds is growing. Obviously, the professor disproves her counterpart in the reading passage.Moreover, despite the reading claims that agriculture activities are threatening the habitats of birds too, the speaker contends that people are paying attentions on the introduction of productive plants instead of occupying more habitats of birds.Finally, the writer insists that the chemical pesticides that used in the agriculture is killing the birds. On the contrary, the professor casts doubt on the writer's opinion by saying that some new pesticides that have no poisons have been invented nowadays and the crops also have ability to resist the insects without using the pesticides.TPO 27（综合）(208 & left one minutes to check )The reading passage explores the issue that the causes of the Little Ice Age. The professor's lecture deals with the same issue. However, he thinks that the reasons that the reading passage provided are out of date, and he use three specific reasons from new researches to support his view.To begin with, even through the reading passage states that the disrupting of the ocean currents should be concerned. The professor argues that the disruption only happened at the European and the North America, so there is no evidence to illustrate the little ice age in theNew Zealand and the South Africa which contradicts what the reading's statement.Moreover, despite the reading passage claims that the clouds produced by the volcanic eruption could coursed the Little Ice Age. But the speaker states that the cloud was not strong enough to course it. It is because, there are other stracting affects happened like the colorful sunlight.Finally, the writer insists that the decreases of human population may contributed the Little Ice Age. On the contrary, the professor puts his doubt on the reading's opinion by saying that the decreases of human population is too short to cause the cooling of the climate, the population growing happened quickly after its decreases.TPO 28（综合）(185 lack of time! 改完227 )The reading passage explores the issue that Rober E.Peary reached the North Pole, the professor's lecture deals with the same issue. However, she thinks that the claim of the Peary is not true, which contradicts what the reading states. And in the lecture, she use three specific reasons to support her view.To begin with, even through the reading passage suggests that the National Geographic Society has invested and admitted the Peary's experience, the professor argues that the committee's conclusion is not objective and can not be trust. It is because that a friend of the Peary in the committee set a fund for his trip, instead of the committee. Obviously, the professor’s argument disprove it’s counterpart in the reading.Moreover, despite the statement in the reading is that a recent expedition provides evidences of the Peary's claim, the speaker contends that the recent expediter can travel that fast because he use airplane to transport the foods, but Peary use seld, so he can not move as fast as the recent expediter did. （没听懂这一段）Finally, the writer of the passage insists that the photographs can support Peary's claim. On the contrary, the professor casts her doubt on the reading's opinion by saying that the photographs is bluer and fade, so it is difficult to prove the photo is be taken at the North Pole.TPO 29（综合）(231 Still have three minutes to check! It is right to type the model at first! )The reading passage explores the issue that the migration of the dinosaurs, the professor's lecture deals with the same issue. However, she thinks that the edmontosaur did not migrate, which contradicts what the reading states. And in the lecture, she used three points to support her view.To begin with, even through the reading passage suggests that the diet of the edmontosaur is a reason that caused its migration, the professor argues in the lecture that the temperature at that age in winter is warmer than today, the North Slope has the 24 degrees a day, so the plants in the winter still grow well. Obviously, the professor’s argument disprove it’s counterpart in the reading.Moreover, despite the statement of the reading that there many skeletons of endmontosaur have been discovered from the same site, the speaker contends that the skeletons can not means the migration, it is also can be explain by the living of the predators of the endmontosaurs at that place.Finally, the writer of the passage insists that the edmonosaurs' physical abilities allow them to migrate that long distances. On the contrary, the professor casts her doubt on the reading's opinion by saying that the young edmonosaurs, the ones that have not be the adults, can not have that fast speed as the developed ones, they can not reach the destination before the witer coming, they are incapable to migrate.TPO 30（综合）(224 only have 54 seconds to check!)The reading passage explores the issue that the Greek weapon "burning mirror", the professor's lecture deals with same issue. However, she thinks that this kind of weapon was real invented, which contradicts what the reading states. And in the lecture, the professor used three specific points to support her view.To begin with, even through the passage suggests that the technology of Greeks at that time is not developed enough to make that weapon, the professor argues that any simple material can be made into parabolic shape easily. Obviously, the professor's argument disproves her counterpart in the reading.Moreover, despite the reading states that it would take a long time to set the wooden ship on fire, the professor contends that the ship was not made by wood, but by peach, which kind of material that can catch fire quickly in seconds and can still burning without the original fire.Finally, the writer of the passage insists that the burning mirror has the similar function with the flaming arrows that the weapon the Greeks already had, but the speaker casts her doubt on what the reading's opinion by saying that the burning mirror set on the ships can not be see it can use to burning ships when use it to attack the enemy, which is different with the flaming arrows.。