chemical sterilization
chemical sterilization
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Heres a familiar story. Youre sitting at the dinner table with a furry, four-legged friend scratching at your feet. When you look down, those cute eyes are almost impossible to resist.What is it about a dogs gaze that makes it so charming? A new study by Japanese scientist Miho Nagasawa seems to have found the answer, and it has to do with something called the cuddle(爱抚)chemical.The cuddle chemical has another, more scientific name: oxytocin. Oxytocin is a substance in the blood that encourages bonding. Levels of oxytocin increase, for example, when a mother feeds her newborn baby. According to Nagasawas study, the same is true when we look deeply into the eyes of a dog.The results of this study can tell us a lot about the history of the bond between humans and dogs. It all started somewhere tens of thousands of years ago. Scientists believe that wolves used to follow humans who were hunting large animals. The wolves would eat the food left behind by the humans.Humans realized that they could use the wolves to help with the hunt, and eventually both species began to work together toward survival.Over time, the wolves that interacted with the humans began to change. They became more loyal to their human partners. The wolves and humans started to depend on each other and bond with each other. These changes are what caused some of the wolves to turn into what we now know as dogs, a new specie^ evolved to better survive in their environment.This process depended a great deal on the bond humans formed with them. And according to Nagasawas study, this bond was formed with the help of oxytocin, the cuddle chemical.11. What do we know about oxytocin?A.It regulates blood flowB.It promotes bondingC.It is in the human geneD.It is good for healthWhen we look deeply into a dog's eyes, the levels of our oxytocin ____.A.reduce over timeB.go either up or downC.are on the riseD.remain unchangedAt the beginning wolves followed humans to ____.A.eat the food left by humansB.guard against large animalsC.take humans for foodD.hunt large animals togetherOver time some wolves turned into dogs ____.A.due to their loyaltyB.due to the changing environmentC.for better survivalD.for better cooperationWhat does Nagasawa9s study aim to do?A.Explore the role of human-wolf partnershipB.Show the characteristics of the cuddle chemicalC.Explain the bond between humans and dogsD.Understand the evolution of species请帮忙给出每个问题的正确答案和分析，谢谢！
4 The Better Agriculture Group (BAG), which has a divisional structure, produces a range of products for the farmingindustry. Divisions B and C are two of its divisions. Division B sells a fertiliser product (BF) to customers external toBAG. Division C produces a chemical (CC) which it could transfer to Division B for use in the manufacture of itsproduct BF. However, Division C could also sell some of its output of chemical CC to external customers of BAG.An independent external supplier to The Better Agriculture Group has offered to supply Division B with a chemicalwhich is equivalent to component CC. The independent supplier has a maximum spare capacity of 60,000 kilogramsof the chemical which it is willing to make available (in total or in part) to Division B at a special price of $55 perkilogram.Forecast information for the forthcoming period is as follows:Division B:Production and sales of 360,000 litres of BF at a selling price of $120 per litre.Variable conversion costs of BF will amount to $15 per litre.Fixed costs are estimated at $18,000,000.Chemical (CC) is used at the rate of 1 kilogram of CC per 4 litres of product BF.Division C:Total production capacity of 100,000 kilograms of chemical CC.Variable costs will be $50 per kilogram of CC.Fixed costs are estimated at $2,000,000.Market research suggests that external customers of BAG are willing to take up sales of 40,000 kilograms of CC at aprice of $105 per kilogram. The remaining 60,000 kilograms of CC could be transferred to Division B for use inproduct BF. Currently no other market external to BAG is available for the 60,000 kilograms of CC.Required:(a) (i) State the price/prices per kilogram at which Division C should offer to transfer chemical CC to DivisionB in order that the maximisation of BAG profit would occur if Division B management implement rationalsourcing decisions based on purely financial grounds.Note: you should explain the basis on which Division B would make its decision using the informationavailable, incorporating details of all relevant calculations. (6 marks)
Air pollutionPeople and air pollution are often in the same places. This means that cities with large populations have the biggest problem of dirty air. Air pollution is caused by many different things. A major kind of air pollution is the gas from cars. Statistics(统计资料) show that 93 percent of all auto trips are within cities.Another major kind of dirty air is the burning of coal and oil for energy. This energy is needed to make electricity. Of course, much more electricity is used in the city than in the county.On the average, we throw away more rubbish than the year before. The burning of rubbish makes air pollution even worse. Many major industries are also responsible for the dirty air in the around cities. The fumes(烟)from iron, steel, chemical, and petrol production add particles(微粒)to the air.The effects of air pollution range from mild headaches to death. The levels of pollution found in heavy traffic may cause headaches for loss of clear vision. Wherever coal and oil are used for fuel, fumes may kill trees and plants and cause metal to corrode(腐蚀). In some of the larger cities, these fumes endanger the lives of human beings by contributing to lung diseases and causing early death.26. The key point of the passage is that().A. the cause of air pollution is peopleB. the causes and the effects of air pollution are both found in citiesC. the effects of air pollution range from headaches to death27. What is the purpose of this passage?A. to persuade people to stop polluting the air().B. to tell the causes of air pollutionC. to tell why cities are bad places to live28. Why is air pollution more grave in the city than in the country?().A. Because there are larger populations in cities.B. Because the air in the city is dirty.C. Because there are much more gas fumes from cars and burning of coal and oil for energy in the city than in the country.29. The fumes from coal and oil may cause metal().A. to corrodeB. to twistC. to turn black30. In larger cities, the fumes from coal and oil may contribute to().A. heart diseaseB. loss of clear visionC. lung diseases
共用题干Eat for a Good and Healthful LifeFood is essential to us as it_________(1)us alive.But recently,research has shown that the eating habits of the average Americans may be dangerous to future ________(2).The foods Americans now choose are often too________(3) in calories（卡路里） and fats. So this article reports a new study: Diet and Health, Implications（含意）for Reducing Chronic Disease Risk.The study,conducted_________(4)the National Research Council's Committee on Diet and Health,__________(5)that balancing nutrition（营养）,calories and activity is the_____(6)to enjoying a long and healthful life.The report recommends that most Americans increase_____(7)activity to a moderate level and make changes in food__________(8)and the amount of calories taken to maintain ideal weight.Most of us-even_________(9)of us at ideal weight-need to eat less fat so _________(10)no more than 30%of our daily calories will come from fat.That means cutting _______ ( 1 1 ) on red meat and whole milk dairy（乳制品） products.Indeed,eat fish,chicken without skin,meats containing little or no fat,and low-fat or no-fat dairy__________(12).The report of the Committee on Diet and Health recommends we eat five or more 1/2- cup servings（一份）of vegetables and fruits___________(13）一especially green and yellow vegetables and such fruits as oranges and lemons.Eating more fruits_________(14)vegetables doesn't have to mean taking increased amounts of calories.Many plant foods are rich in nutritional substances:they provide many vitamins and minerals for very few__________(15)._________(7) A: public B:spare C: physical D: chemical
共用题干第二篇Night of the Living AntsWhen an ant dies,other ants move the dead insect out of the nest.This behavior is interesting to scien-tists,who wonder how ants know for sure一and so soon一that another ant is dead.Dong-Hwan Choe,a scientist at the University of California,found that Argentine ants have a chemical on the outside of their bodies that signals to other ants,"I'm dead一take me away."But there's a twist to Choe's discovery. These ants behave a little bit like zombies（僵尸）.Choe says that the living ants一not just the dead ones一have this death chemicals. In other words,while an ant crawls around,perhaps in a picnic or home,it's telling other ants that it's dead.What keeps ants from hauling away the living dead? Choe found that Argentine ants have two additional chemicals on their bodies,and these tell nearby ants something like,"Wait一I'm not dead yet."So Choe's research turned up two sets of chemical signals in ants:one says,"I'm dead,"the other set says,"I'm not dead yet."Other scientists have tried to figure out how ants know when another ant is dead.If an ant is knockedunconscious,other ants leave it alone until it wakes up.That means ants know that unmoving ants can still be alive.Choe suspects that when an Argentine ant dies,the chemical that says"Wait一I'm not dead yet"quickly goes away. Once that chemical is gone,only the one that says"I'm dead"is left."It's because the dead ant no longer smells like a living ant that it gets carried to the graveyard（墓地）,not because its body releases new,unique chemicals after death,"said Choe.When other ants detect the"dead"chemical without the"not dead yet" chemical,they haul away the body. This was Choe's hypothesis（假设）.To test his hypothesis,Choe and his team put different chemicals on Argentine ant pupae（蛹）.When the scientists used the"I'm dead"chemical,other ants quickly hauled the treated pupae away.When the sci-entists used the"Wait一I'm not dead yet"chemical,other ants left the treated pupae alone.Choe believes this behavior shows that the" not dead yet" chemical overrides（优先于）the" dead" chemical when picked up by adult ants.And that when an ant dies,the"not dead yet"chemical fades away.Other nearby ants then de-tect the remaining"dead"chemical and remove the body from the nest.According to Choe's hypothesis,_______________.A:an ant still smells like a living one when it diesB:the"I am dead"chemical leaves the ant's body when it diesC:the"I am not dead yet"chemical is left when an ant diesD:the"I am not dead yet"chemical quickly goes away when it dies
共用题干第二篇Night of the Living AntsWhen an ant dies,other ants move the dead insect out of the nest.This behavior is interesting to scien-tists,who wonder how ants know for sure一and so soon一that another ant is dead.Dong-Hwan Choe,a scientist at the University of California,found that Argentine ants have a chemical on the outside of their bodies that signals to other ants,"I'm dead一take me away."But there's a twist to Choe's discovery. These ants behave a little bit like zombies（僵尸）.Choe says that the living ants一not just the dead ones一have this death chemicals. In other words,while an ant crawls around,perhaps in a picnic or home,it's telling other ants that it's dead.What keeps ants from hauling away the living dead? Choe found that Argentine ants have two additional chemicals on their bodies,and these tell nearby ants something like,"Wait一I'm not dead yet."So Choe's research turned up two sets of chemical signals in ants:one says,"I'm dead,"the other set says,"I'm not dead yet."Other scientists have tried to figure out how ants know when another ant is dead.If an ant is knockedunconscious,other ants leave it alone until it wakes up.That means ants know that unmoving ants can still be alive.Choe suspects that when an Argentine ant dies,the chemical that says"Wait一I'm not dead yet"quickly goes away. Once that chemical is gone,only the one that says"I'm dead"is left."It's because the dead ant no longer smells like a living ant that it gets carried to the graveyard（墓地）,not because its body releases new,unique chemicals after death,"said Choe.When other ants detect the"dead"chemical without the"not dead yet" chemical,they haul away the body. This was Choe's hypothesis（假设）.To test his hypothesis,Choe and his team put different chemicals on Argentine ant pupae（蛹）.When the scientists used the"I'm dead"chemical,other ants quickly hauled the treated pupae away.When the sci-entists used the"Wait一I'm not dead yet"chemical,other ants left the treated pupae alone.Choe believes this behavior shows that the" not dead yet" chemical overrides（优先于）the" dead" chemical when picked up by adult ants.And that when an ant dies,the"not dead yet"chemical fades away.Other nearby ants then de-tect the remaining"dead"chemical and remove the body from the nest.The passage"Night of the Living Ants"tells us about_______________.A:how an ant is moved out of the nest at nightB:what an ant does at nightC:how an ant finds its way in darknessD:what happens when an ant dies
共用题干第二篇Night of the Living AntsWhen an ant dies,other ants move the dead insect out of the nest.This behavior is interesting to scien-tists,who wonder how ants know for sure一and so soon一that another ant is dead.Dong-Hwan Choe,a scientist at the University of California,found that Argentine ants have a chemical on the outside of their bodies that signals to other ants,"I'm dead一take me away."But there's a twist to Choe's discovery. These ants behave a little bit like zombies（僵尸）.Choe says that the living ants一not just the dead ones一have this death chemicals. In other words,while an ant crawls around,perhaps in a picnic or home,it's telling other ants that it's dead.What keeps ants from hauling away the living dead? Choe found that Argentine ants have two additional chemicals on their bodies,and these tell nearby ants something like,"Wait一I'm not dead yet."So Choe's research turned up two sets of chemical signals in ants:one says,"I'm dead,"the other set says,"I'm not dead yet."Other scientists have tried to figure out how ants know when another ant is dead.If an ant is knockedunconscious,other ants leave it alone until it wakes up.That means ants know that unmoving ants can still be alive.Choe suspects that when an Argentine ant dies,the chemical that says"Wait一I'm not dead yet"quickly goes away. Once that chemical is gone,only the one that says"I'm dead"is left."It's because the dead ant no longer smells like a living ant that it gets carried to the graveyard（墓地）,not because its body releases new,unique chemicals after death,"said Choe.When other ants detect the"dead"chemical without the"not dead yet" chemical,they haul away the body. This was Choe's hypothesis（假设）.To test his hypothesis,Choe and his team put different chemicals on Argentine ant pupae（蛹）.When the scientists used the"I'm dead"chemical,other ants quickly hauled the treated pupae away.When the sci-entists used the"Wait一I'm not dead yet"chemical,other ants left the treated pupae alone.Choe believes this behavior shows that the" not dead yet" chemical overrides（优先于）the" dead" chemical when picked up by adult ants.And that when an ant dies,the"not dead yet"chemical fades away.Other nearby ants then de-tect the remaining"dead"chemical and remove the body from the nest.Which of the following statements is NOT true of ants?A:Ants know very soon that?another ant is dead.B:When an ant is dead,others move its body out of the nest.C:If an ant is unconscious,it is moved out of the nest.D:Living ants have the"I'm dead"chemical on their bodies.
共用题干第二篇Night of the Living AntsWhen an ant dies,other ants move the dead insect out of the nest.This behavior is interesting to scien-tists,who wonder how ants know for sure一and so soon一that another ant is dead.Dong-Hwan Choe,a scientist at the University of California,found that Argentine ants have a chemical on the outside of their bodies that signals to other ants,"I'm dead一take me away."But there's a twist to Choe's discovery. These ants behave a little bit like zombies（僵尸）.Choe says that the living ants一not just the dead ones一have this death chemicals. In other words,while an ant crawls around,perhaps in a picnic or home,it's telling other ants that it's dead.What keeps ants from hauling away the living dead? Choe found that Argentine ants have two additional chemicals on their bodies,and these tell nearby ants something like,"Wait一I'm not dead yet."So Choe's research turned up two sets of chemical signals in ants:one says,"I'm dead,"the other set says,"I'm not dead yet."Other scientists have tried to figure out how ants know when another ant is dead.If an ant is knockedunconscious,other ants leave it alone until it wakes up.That means ants know that unmoving ants can still be alive.Choe suspects that when an Argentine ant dies,the chemical that says"Wait一I'm not dead yet"quickly goes away. Once that chemical is gone,only the one that says"I'm dead"is left."It's because the dead ant no longer smells like a living ant that it gets carried to the graveyard（墓地）,not because its body releases new,unique chemicals after death,"said Choe.When other ants detect the"dead"chemical without the"not dead yet" chemical,they haul away the body. This was Choe's hypothesis（假设）.To test his hypothesis,Choe and his team put different chemicals on Argentine ant pupae（蛹）.When the scientists used the"I'm dead"chemical,other ants quickly hauled the treated pupae away.When the sci-entists used the"Wait一I'm not dead yet"chemical,other ants left the treated pupae alone.Choe believes this behavior shows that the" not dead yet" chemical overrides（优先于）the" dead" chemical when picked up by adult ants.And that when an ant dies,the"not dead yet"chemical fades away.Other nearby ants then de-tect the remaining"dead"chemical and remove the body from the nest.According to Paragraph 7,what is the result. of the test on Choe's hypothesis? A:It shows that his hypothesis is wrong.B:It proves that his hypothesis is convincing.C:It suggests that his hypothesis needs revising.D:Not enough evidence has been found to support his hypothesis.
共用题干第二篇Night of the Living AntsWhen an ant dies,other ants move the dead insect out of the nest.This behavior is interesting to scien-tists,who wonder how ants know for sure一and so soon一that another ant is dead.Dong-Hwan Choe,a scientist at the University of California,found that Argentine ants have a chemical on the outside of their bodies that signals to other ants,"I'm dead一take me away."But there's a twist to Choe's discovery. These ants behave a little bit like zombies（僵尸）.Choe says that the living ants一not just the dead ones一have this death chemicals. In other words,while an ant crawls around,perhaps in a picnic or home,it's telling other ants that it's dead.What keeps ants from hauling away the living dead? Choe found that Argentine ants have two additional chemicals on their bodies,and these tell nearby ants something like,"Wait一I'm not dead yet."So Choe's research turned up two sets of chemical signals in ants:one says,"I'm dead,"the other set says,"I'm not dead yet."Other scientists have tried to figure out how ants know when another ant is dead.If an ant is knockedunconscious,other ants leave it alone until it wakes up.That means ants know that unmoving ants can still be alive.Choe suspects that when an Argentine ant dies,the chemical that says"Wait一I'm not dead yet"quickly goes away. Once that chemical is gone,only the one that says"I'm dead"is left."It's because the dead ant no longer smells like a living ant that it gets carried to the graveyard（墓地）,not because its body releases new,unique chemicals after death,"said Choe.When other ants detect the"dead"chemical without the"not dead yet" chemical,they haul away the body. This was Choe's hypothesis（假设）.To test his hypothesis,Choe and his team put different chemicals on Argentine ant pupae（蛹）.When the scientists used the"I'm dead"chemical,other ants quickly hauled the treated pupae away.When the sci-entists used the"Wait一I'm not dead yet"chemical,other ants left the treated pupae alone.Choe believes this behavior shows that the" not dead yet" chemical overrides（优先于）the" dead" chemical when picked up by adult ants.And that when an ant dies,the"not dead yet"chemical fades away.Other nearby ants then de-tect the remaining"dead"chemical and remove the body from the nest.What is meant by"death chemical"mentioned in Paragraph 3?A:A chemical that contains poison.B:A chemical that causes death.C:A chemical that announces death.D:A chemical that prevents death.
共用题干Animal's"Sixth Sense"A tsunami was triggered by an earthquake in the Indian Ocean in December,2004.It killed tens of thou- sands of people in Asia and East Africa. Wild animals,______________(51),seem to have escaped that terrible tsunami.This phenomenon adds weight to notions that they possess a"sixth sense"for______________(52),cx-perts said.Sri Lankan wildlife officials have said the giant waves that killed over 24,000 people along the Indian Ocean island's coast clearly______________(53)wild beasts,with no dead animals found."No elephants are dead,not______________(54)a dead rabbit.I think animals can______________(55) disaster.They have a sixth sense.They know when things are happening."H.D.Ratnayake,deputy director of Sri Lanka's Wildlife Department,said about one month after the tsunami attack.The______________(56) washed floodwaters up to 2 miles inland at Yala National Park in the ravaged southeast,Sri Lanka's biggest wildlife______________(57)and home to hundreds of wild elephants and several leopards."There has been a lot of______________(58)evidence about dogs barking or birds migrating before vol- came eruptions or earthquakes.But it has not been proven,"said Matthew van Lierop an animal behavior ______________(59)at Johannesburg Zoo."There have been no______________(60)studies because you can't really test it in a lab or field set-ting,"he told Reuters.Other authorities concurred with this______________(61)."Wildlife seem to be able to pick up certain______________(62),especially birds…there are many re-ports of birds detecting impending disasters."said Clive Walker,who has written several books on African wildlife.Animals_______________(63)rely on the known senses such as smell or hearing to avoid danger such as predators.The notion of an animal"sixth sense”-or_______________(64)other mythical power一is an enduring one which the evidence on Sri Lanka's ravaged coast is likely to add to.The Romans saw owls______________(65)omens of impending disaster and many ancient cultures viewed elephants as sacred animals endowed with special powers or attributes._________(58)A:experimentalB:apparentC:scientificD:chemical