AN ALTERNATING DIGITAL TREE (ADT) ALGORITHM FOR 3D GEOMETRIC SEARCHING AND INTERSECTION PROBLEMS
新高考八省最新名校联考试题汇编：专题 03 阅读理解 (七选五) (原卷版)
专题03 阅读理解之七选五新高考八省最新名校联考试题汇编（原卷版）1.【重庆市南开中学校2022-2023学年高三上学期期中英语试题】Climate change has increased average temperatures by 1℃ over the past century, making heat waves more frequent and intense than those from any other point in recorded history. ____36____ A study published in the journal Nature Climate Change found global warming responsible for 37 percent of heat-related deaths between 1991 and 2018.The following is what happens if you’re the next to be killed. First, your brain sends a series of messages to your sweat glands telling them to increase sweat production. Then your heart starts beating faster to pump blood to the skin while blood flow is directed away from important organs(器官) like your liver, kidneys and gut.____37____If heat stroke occurs, your body might get hot and direct so much oxygen-rich blood to the skin that it suffocates(把…闷死) vital internal organs. If your body fails to cool you down, its internal temperature might start to climb from a normal level to about 104 degrees. ____38____ You may feel it start as a dull headache. Before long, you might lose consciousness. Your brain might begin to swell.While you struggle to stay awake and avoid dizzying confusion, the excessive internal heat is damaging your gut, consequently causing an inflammatory(发炎的) response. ____39____That’s just part of what we know about how extreme heat kills you. ____40____ A lot of what we know comes from studies on animal models, like mice and rats, or from examinations of people dying of heat stroke.A．As the heat rises quickly, so does the death number.B．That’s because we can’t study it in humans in the laboratory.C．As temperatures tick ever higher, that figure may well rise.D．At that temperature, your brain becomes affected.E．Surviving the organ failure might require an emergency transplant.F．Sometimes that alone is enough to create problems for a weak or aging heart.G．Left untreated, what follows is a flood of organ failure that leads to your death.2.【辽宁省名校联盟2022-2023学年高三12月联考】It is no secret that technology is fast taking up education in almost every part of the world. Most educators will agree that learning is taking a considerable turn-around to welcome digital teaching both in and out of the class.____16____ So there is a need to assess these materials to identify suitable and satisfactory ways. That is why, when adopting digital textbooks as an educator or school, you must consider several factors below.Content InteractionIs the content in the digital textbook interactive enough? It is a crucial question that needs to get looked into as educators begin fully on digital teaching. As an educational participant, ensure that the 3D images, sounds, videos, and diagrams in the digital content can keep learners engaged for an extended period. ____17____ Reliability of Educational AppsImportantly, if you are an aggressive educator, you will always want the best for your students. Ensure that you choose reliable educational applications that won’t let you down as a teacher. ____18____ Pedagogue is an application with everything you need to conduct a virtual digital classroom using e-textbooks. It is a fantastic app that would help you master excellent ways to integrate e-textbooks into your classrooms.Affordability and Accessibility____19____ Besides, easy access to the Internet in educational institutions is a significant aspect to consider when using digital books in schools. Moreover, education apps with digital textbooks should have updated learning content easily downloadable in students’ tablets and smartphones. This way, teaching will get easier leading to comfortable learning by a variety of students.Modern educators are tasked with ensuring that content delivery is an excellent and fun activity. ____20____ That is why it is critical to make sure that the digital textbooks we adopt and choose for our students are the best and can motivate critical thinking in our students’ minds.A．It’s believed that learning is a laboring process.B．Digital content should become cheaper than print textbooks.C．E-textbooks should help learners with content understanding.D．You should have apps on your phones with well-researched content.E．They ought to ensure education is meaningful and productive for the learners.F．Hence, this would make their learning not only interactive but also enjoyable.G．Similarly, students’ preference for digital learning materials continues to expand.3.【江苏省赢在新高考2022-2023学年高三12月大联考】For anyone trying to lose weight, one of the first indulgences (嗜好) to get cut from their diet is alcohol. After all, a good-size glass of wine contains more than 150 calories. ____16____ New findings from researchers reveal that women who drink moderately (适量) are less likely to gain weight than those who don’t.Researchers conducted a study of women’s drinking habits and weight gain. The researchers asked the women about their alcohol intake and measured each volunteer’s weight. ____17____ The researchers also considered some potential factors, such as age, smoking, physical activity and other lifestyle. ____18____ ____19____ First, it appeared that the women who drank the most got fewer of their total calories from other sources than other women, Second, there is evidence that alcohol may cause physiological changes to appetite that may drive women to lose weight as they drink more.This study suggests that you can probably make room for moderate alcohol consumption and not have it result in weight gain. ____20____ Previous studies have shown that drinking alcohol can lead to a greater risk of developing breast cancer. So whatever potential gains a glass of wine may have on slimming down the waist, the benefits must be balanced against the other potential risks of alcohol consumption.A．Several possibilities can account for the link.B．A small glass of wine per day is an unwise choice.C．But maybe it’s time to put wine glasses back on the table.D．The more alcohol women consumed, the slimmer they would be.E．But we don’t advise people to drink more alcohol to control weight.F．Those drinking a certain amount of alcohol daily were of normal weight.G．But the link existed between alcohol intake with a low risk of gaining weight.4.【湖南省部分学校2022-2023学年高三一轮复习联考】Working on ships is not an easy task and dissatisfaction and deactivation can easily be developed among seafarers as a result of various kinds of stresses. ____36____ Therefore, captain should take additional steps as mentioned below to ensure that all team members are comfortable with each other both on and off work.The morning meeting, which is conducted to assign work to team members, is the best time to get all the crew members together. It is necessary that crew members talk to each other during such meetings. ____37____ This activity gives members a sense of responsibility and importance. It also works a great deal in improving their performance and interpersonal relationship.On-board training program is yet another important opportunity to get crew members together to instruct important working knowledge or conduct safety committee meetings. ____38____ Spend free time together. It is often seen that post working hours, officers and crew members spend time in their own rooms instead of getting together in offices or crew lounge. Watching movies and playing games in free time is a solid way to know each other and build great relationships both on and off work.____39____ Party is a great method to bond people together and improve scarred relationships on board ships. However, it is necessary that they are arranged in such a way that maximum crew is able to participate. Festival celebrations are also a great way to enhance interpersonal relationships between people onboard.The above-mentioned methods are some of the main ones that are used onboard to strengthen relationships on board ships. ____40____ And it would also improve productivity and employment satisfaction.A．During such situation, it is up to captain.B．A “one-man-show” cannot run the whole sh ip.C．Everyone likes to party and unwind once in a while.D．Each member should be given a chance to provide suggestions.E．Doing this would ensure smooth and safe operations of the ship.F．Captain should arrange the training for maximum crew members to participate.G．This is the most important step towards developing interpersonal relationship on board ships.5.【辽宁省六校2022-2023学年高三上学期期中联考】“What is your problem?” So simple and yet so difficult to answer, that essential question is what I ask my high school engineering students when they begin the study of inventions. Our students are often provided with the problem, or spoon-fed with a solution, or end up checking their answers against those in the back of thebook.___36___The concept is the “invention design process” or “engineering design process”.___37___These steps include identifying a practical problem, developing potential solutions and ultimately designing something that proves they can improve the lives of beneficiaries. In short, we are talking about real problems that affect real people.Students will often say, “___38___” My reply is similar: “I don’t either, but it is going to be a lot of fun seeing you find one.” At this point in the process, students begin to realize that not only do they need to identify a problem, but they have to clearly understand it. There is no room for loosely pieced together projects without thought or true purpose.For example, each term my class invents devices to assist local fire and police departments. At the end of the unit, we invite police officers and firefighters to a showcase who then provide students with feedback (反馈) on the devices.___39___As a result, the students will also give their projects serious attention.Inventing is a skill and every student can develop that skill. It may be a cliché (陈词滥调), but it’s true — kids are natural inventors. And once they are taught the skills of how to invent, there is no stopping them. As a teacher, I can’t help but ask, “___40___”A．I don’t know the answer to the proble m.B．I don’t know what problem I should solve.C．Now I am introducing them to a foreign concept.D．It involves students in completing a series of steps.E．How could you not give the problem the attention it deserves?F．How can I not want to send more problem-solvers into the world?G．They do not have time to waste on projects that don’t take their work seriously.6.【湖南师范大学附属中学2022-2023学年高三上学期月考】Have you ever wished you didn’t have to wake up early and go all the way to school? For 700,000 American kids, this wish comes true.___36___This kind of learning has different names: online learning or distance learning. Regardless of what it is called, this idea may create an impression of a lonely kid reading pages of information on a computer screen rather than from a book or an image of another kid spending the day playing video games instead of learning mathematics or reading a book. Where online education is concerned, both of these are false! Actually, online learning simply means learning differently.___37___Flexibility is the main advantage. Students can attend school wherever and whenever they desire. Homework can be turned in from anywhere the student has Internet access. Additionally, many online schools willallow students to work at their own pace.Another advantage of online schooling is with the variety of courses. Most online schools teach the same basic classes like English, math, science, and history.___38___However, traditional schools are often unable to offer these types of classes if there are not enough students.Online schools also have different types of learning tools for kids to use. For example, many online schools have special Web sites where only students registered in online classes can watch videos, see lessons presented, or chat with teachers and other students. Some online schools have live class times where students can call and talk with the teacher directly. ___39___Computer technology is amazing, and we use computers for chatting with our friends, listening to music, and playing games.___40___Since 2012, at least 38 states either have had their own online schools or made rules for students attending them. It looks like online schools are here to stay, but only you can decide if this type of learning is right for you.A．Online schools offer many benefits for the learners.B．Of course, there are some disadvantages of going to school online.C．Almost every part of our lives is affected by it, and school is no exception.D．They attend school over the Internet using ordinary home or library computers.E．Other online schools even have online clubs where kids can talk about their hobbies.F．Some online schools also offer specialized classes in subjects such as space science, French, or zoology. G．For some students, online school may be ideal, but for others, traditional school may better meet their needs.7.【湖北省十一校2022-2023学年高三联考】People are taught how to speak, but good sentence structure and a wide range of vocabulary words won’t always lead to being understood or understanding others._______16_______The good news is that it’s never too late to learn how to communicate more effectively. The first step is to realize you’ re having communication issues._______17_______The following is a list of the top three signs that you need to learn healthier communication skills.You have the same fights over and over.Your fights are about the same topic again and again. If this is happening, it means you don’t yet have the skills to resolve conflicts._______18_______The fight may end, but it’s only a matter of time before you argue about the same thing again. When you learn how to resolve conflicts, issues don’t pile up or become baggage that weighs down your relationship._______19_______You don’t want to fight so you try not to bring up subjects th at lead only to pain and disconnection. The problem is that avoiding them leads to pain and disconnection anyway. Unless you learn how to have hard conversations productively, you will get more and more disconnected until your relationship is in danger of ending.You regularly feel misunderstood or unheard.No matter how hard you try, you don’t feel understood. Perhaps your partner has expressed the samefeeling.Over time the disconnected feeling does damage to your relationship. It’s important to learn how to communicate in a better way, so that both you and the other person feel heard andunderstood._______20_______To be heard, your partner will need to learn how to listen. For you, to be able to hear your partner, you will need to do the same.A．You avoid discussing certain topics.B．You argue with your partners about some issues.C．If you can’t resolve issues, they will continue to show up.D．This requires more than just speaking to your partner or vice versa.E．Then, you can learn how to communicate in a more productive way.F．If you leave conflicts unsettled, you will feel disconnected and lonely.G．Effective communication requires much more than being able to speak.8.【2022-2023学年河北省石家庄市二中高三期中考试】Gratitude is more than just saying “thank you” to someon e who has helped us or given us a gift. ___16___ And this positive emotion can be good for our emotional and physical health, as well as the health of our relationships.One reason for this is that gratitude stops us from thinking about negative emotions. Writing a “thank you” letter, for example, shifts our attention so that we focus on positive emotions. Even if we don’t share our writing with anyone, the act of completing the exercise alone makes us happier and more satisfied with life. And this gets better with time. As we are essentially training our brain to be more in tune with noticing the positive, after several weeks or months, this becomes more intuitive(直觉的). ___17______18___ Studies prove gratitude can improve sleep quality, better eating habits, and reduced inflammation(炎症) in people who have had heart problems.Gratitude is clearly good for us, but is it also good for the people in our lives? ___19___ When shared, spoken or written gratitude is about feeling valued and helping others feel valued too. Feeling valued can help build stronger relationships with family, partners, friends or even colleague. And that’s on top of all the other ways gratitude is clearly good for us.Many studies show expressing gratitude benefits people a lot including the emotional, mental and physical health etc. ___20___ Let’s stop counting sheep or calorie and start counting our blessings instead.A．So why not do so?B．The simple answer is “yes”C．We should form good habits in our daily work.D．Gratitude can also make us feel good in our bodies.E．The more we express gratitude, the more positive we feel.F．How to describe the relationship between gratitude and complaint?G．It’s a deeper appreciation for someone or something making us feel positive.9.【广东省华南师范大学附属中学2022-2023学年高三】Many of our memory systems are driven by one single, powerful urge: to survive. We seem to have an inborn instinct(本能) to remember routes, so we can navigate our local environments safely. ___16___Ever since we lived in groups, us humans have needed to know who’s “part of the group”, and who isn’t, as a vital part of staying safe. And we’re excellent at remembering things that might put our wellbeing at risk. A recent research study showed that we’re remarkably accurate at recall ing anything connected with infection.In the study, volunteers were shown a set of objects that they would be tested on later. But there was a twist. Some of the items were held by a researcher who was said to have COVID．And guess what? ___17___None of the volunteers would ever have to touch those things themselves. But their minds still prioritised them, locking in the information for later—just in case it could keep them safe._____18_____When you’ve got something important to remember, why not “tag” it with one of those unpleasant feelings that your brain can’t help holding on to?• ______19______Picture the bottle, and imagine opening it only to discover that it’s weeks out of date. Think about how it would look—and smell! Thanks to the power of disgust, you’ll have a much better chance of remembering to buy what you need.• Maybe you have to visit the library before it closes. To refresh your memory, visualise the library tables piled high with all the foods you absolutely hate. See if your instinct for self-protection keeps the library in your thoughts more than normally!• And how about learning the password for your credit card by imagining that only the correct buttons on the ATM are safe? The first time you type the password, pretend that all the other keys are covered in deadly germs.______20______Don’t try this technique too often, though, or you’ll end up always feeling on edge! But when your memory needs a boost a small bit of disgust can be very healthy for your recall.A．Make use of your drive to survive.B．And it’s what you can use to your advantage.C．Keep the “dangerous” pattern on your memory.D．We’re also naturally talented at recognising faces.E．Even imaginary dangers can sharpen our memory skills.F．Worried about forgetting the milk from your shopping list?G．Those “infected” objects proved to be significa ntly easier to recall.10.【福建省福州市三校2022-2023学年高三上学期期中联考英语试题】Empathy, the ability to understand and co-experience the feelings and thoughts of other people, is probably one of the most important skills a person can have. ____36____• Humans are social animals.There are very few activities that humans take part in that don’t involve others. ____37____It allows you toperceive others’ motives, treat them the way they want to be treated, understand how others perceive you, and so on.• It lets you better understand non-verbal components of communication.____38____People who are not empathetic have a hard time reading between the lines of conversations. They cannot understand that what the other person means to communicate is different from what they actually say.• ____39____When you unconsciously perceive what the other party wants and needs and can understand exactly why they want it, reaching a “win-win” solution gets easier. You don’t have to blindly search for a way out.• It broadens your horizons.Seeing the world from other people’s perspectives lets you perceive it to a fuller extent. When you are able to look at life from other people’s point of view, you are able to live a more fulfilled life.____40____Thus, achieving higher levels of empathy often means achieving greater fulfilment as human beings.A．It makes you better at handling conflicts.B．It helps you introduce your ideas to others.C．Empathy basically is what makes us human.D．Humans always live and work with each other.E．So why exactly is empathy so important for us?F．Communication is so much more than what words express.G．Therefore, the ability to better understand others and read their feelings is an advantage.高考质量提升是一项系统工程，涉及到多个方面、各个维度，关键是要抓住重点、以点带面、全面突破，收到事半功倍的效果。
高二英语科技词汇单选题40题(带答案)
高二英语科技词汇单选题40题(带答案)1.The new smartphone has a large _____.A.screenB.keyboardC.mouseD.printer答案：A。
“screen”是屏幕，新智能手机有一个大屏幕，符合常理。
“keyboard”是键盘，“mouse”是鼠标，“printer”是打印机，都与智能手机不匹配。
2.We can use a _____ to take pictures.puterB.cameraC.televisionD.radio答案：B。
“camera”是相机，可以用来拍照。
“computer”是电脑，“television”是电视，“radio”是收音机，都不能用来拍照。
3.The _____ can play music and videos.ptopB.speakerC.projectorD.scanner答案：A。
“laptop”是笔记本电脑，可以播放音乐和视频。
“speaker”是扬声器，“projector”是投影仪，“scanner”是扫描仪，都不能播放音乐和视频。
4.My father bought a new _____.A.tabletB.bookC.penD.pencil答案：A。
“tablet”是平板电脑。
“book”是书，“pen”是钢笔，“pencil”是铅笔，只有平板电脑是科技设备。
5.The _____ is very useful for online meetings.A.headphoneB.microphoneC.speakerD.camera答案：D。
“camera”摄像头在在线会议中很有用。
“headphone”是耳机，“microphone”是麦克风，“speaker”是扬声器，都不如摄像头在在线会议中的作用直接。
6.We can store a lot of data in a _____.A.flash driveB.penC.pencilD.book答案：A。
英语作文通过数字永生技术延长生命
英语作文通过数字永生技术延长生命全文共3篇示例，供读者参考篇1Advancements in technology have revolutionized many aspects of our lives, including the field of medicine. In recent years, scientists have made significant progress in the development of a groundbreaking technology known as digital immortality, which aims to extend human life span indefinitely through the preservation of consciousness and memories in a digital format.Digital immortality involves the use of advanced computer algorithms and artificial intelligence to create a virtual replica of a person's mind and consciousness. Through the storage of personal data, memories, and brain scans, individuals can theoretically live on indefinitely in a digital form even after their physical body has ceased to exist.One of the key benefits of digital immortality is the potential to significantly extend human life span and potentially achieve immortality. By transferring one's consciousness and memories into a digital format, individuals can continue to exist in asimulated environment long after their physical body has passed away. This has the potential to revolutionize the concept of death and open up new possibilities for expanding the human lifespan.Furthermore, digital immortality offers the opportunity for individuals to preserve their personal legacies and memories for future generations. By storing a wealth of data and information about one's life experiences, relationships, and accomplishments, individuals can ensure that their memories and stories are passed down to future generations in a format that is accessible and interactive.Additionally, digital immortality has the potential to revolutionize the fields of healthcare and medicine by offering new ways to treat and prevent age-related diseases and disorders. By analyzing vast amounts of data collected from individuals' digital consciousnesses, scientists can gain valuable insights into the aging process and develop innovative therapies and interventions to extend human life span and improve quality of life.Despite the many potential benefits of digital immortality, there are also ethical and philosophical considerations that must be taken into account. Questions about the nature ofconsciousness, the preservation of personal identity, and the implications of living indefinitely in a digital format are some of the key issues that need to be addressed as this technology continues to develop.In conclusion, digital immortality represents a transformative and revolutionary technology that has the potential to redefine the concept of death and revolutionize the way we think about life and consciousness. While there are still many challenges and uncertainties to overcome, the development of digital immortality holds immense promise for extending human life span and preserving personal legacies for future generations.篇2Advancements in technology have always been aimed at improving our quality of life, and one of the most groundbreaking developments in recent years is the concept of digital immortality. Scientists and researchers are exploring the possibility of extending human life by uploading our consciousness onto a digital platform, allowing us to live forever in the virtual realm.The idea of achieving eternal life through technology may seem like something out of a science fiction novel, but it isactually becoming a very real possibility. By digitizing our memories, thoughts, and personalities, we could potentially live on long after our physical bodies have ceased to exist. This concept raises a host of ethical and philosophical questions, but there is no denying the incredible potential that this technology holds.One of the key benefits of digital immortality is the ability to preserve our knowledge and experiences for future generations. Imagine being able to pass down not just physical possessions, but your entire self to your children and grandchildren. Your wisdom, your stories, your essence - all kept alive in the digital world for eternity.Furthermore, digital immortality could revolutionize the way we think about death and grief. Instead of mourning the loss of a loved one, we could take solace in the fact that their consciousness lives on in a digital form. We could interact with them, talk to them, and continue to learn from them long after they have passed away.Of course, there are also potential downsides to this technology. The idea of living forever raises questions about overpopulation, resource allocation, and the potential for digital identities to be hacked or manipulated. And then there is thequestion of whether digital immortality would truly capture the essence of what it means to be human, or whether it would simply be a shallow imitation of life.Despite these concerns, the concept of digital immortality is an incredibly exciting prospect. It has the potential to transform our understanding of life and death, and to fundamentally alter the way we relate to the world around us. While the technology is still in its early stages, the possibilities it presents are endless.In conclusion, the idea of achieving eternal life through digital means is a fascinating concept that holds incredible promise for the future of humanity. As scientists continue to explore the possibilities of digital immortality, we can only begin to imagine the ways in which it will reshape our world. Whether or not we will one day be able to upload our consciousness and live forever remains to be seen, but one thing is for certain - the future of technology is full of endless possibilities.篇3Title: Extending Life through Digital Immortality TechnologyIn recent years, the development of technology has brought numerous breakthroughs in the field of medicine and healthcare. One of the most revolutionary advancements is the concept ofdigital immortality, which aims to use advanced computer algorithms and artificial intelligence to create virtual versions of individuals that can interact and communicate with loved ones even after their physical death.Digital immortality technology works by collecting vast amounts of data about an individual, including their memories, personality traits, and mannerisms, and then using this information to create a digital avatar that accurately replicates the person's thoughts and behavior. These avatars can be programmed to respond to questions and engage in conversations, allowing friends and family members to continue interacting with their loved ones long after they have passed away.The potential benefits of digital immortality are immense. For one, it offers a way for individuals to preserve their memories and experiences for future generations, ensuring that their legacy lives on even after they are gone. It also provides a sense of comfort and closure to those left behind, allowing them to continue their relationships with their deceased loved ones in a meaningful way.Additionally, digital immortality technology has the potential to significantly impact the field of healthcare byextending the human lifespan. By creating digital copies of individuals, doctors and researchers can study the effects of different treatments and interventions on these avatars, allowing them to develop personalized healthcare plans that are tailored to each person's unique genetic makeup and medical history. This could lead to more effective treatments for a wide range of illnesses and diseases, ultimately helping people live longer, healthier lives.In conclusion, digital immortality technology holds great promise for extending the human lifespan and preserving the memories of loved ones. While there are still many ethical and technical challenges to overcome, the potential benefits of this technology are significant and cannot be ignored. As we continue to push the boundaries of science and technology, digital immortality may soon become a reality, forever changing the way we approach life and death.。
5g网络雅思作文
5g网络雅思作文The advent of 5G networks has ushered in a new era of technological advancement, transforming the way we communicate, access information, and interact with the world around us. This revolutionary technology, with its unprecedented speed, capacity, and responsiveness, holds immense potential to revolutionize various sectors, bringing about profound societal and economic changes. At its core, 5G represents a significant leap forward from its predecessor, 4G. It operates on a higher frequency spectrum, enabling significantly faster datatransfer rates. This enhanced speed translates into a seamless online experience, with instantaneous downloads, buffer-free streaming, and crystal-clear video calls. The increased capacity of 5G networks allows for a far greater number of devicesto connect simultaneously without compromising performance, facilitating the proliferation of interconnected devices, often referred to as the "Internet of Things." Moreover, 5G boasts remarkably low latency, the delay between a request and a response, making real-time applications, such as remote surgery and autonomous driving, a tangible reality. The implications of 5G technology extendfar beyond enhanced connectivity. In the realm of healthcare, 5G enables remote patient monitoring, telemedicine consultations, and the seamless transmission of large medical imaging files. Surgeons can perform complex procedures remotely, leveraging the precision and responsiveness of 5G networks. Patients in remote areas can access specialized medical expertise through video conferencing,breaking down geographical barriers to healthcare access. The ability to collect and analyze vast amounts of health data in real-time opens up new avenues for disease prevention, diagnosis, and treatment. The manufacturing industry ispoised for a significant transformation with the integration of 5G. Smart factories, powered by 5G connectivity, leverage interconnected sensors, robots,and automation systems to optimize production processes, enhance efficiency, and reduce costs. Real-time data analysis enables predictive maintenance, minimizing downtime and maximizing productivity. The increased reliability andresponsiveness of 5G networks ensure seamless communication between machines, facilitating a truly interconnected manufacturing ecosystem. In the realm of transportation, 5G is a key enabler of autonomous vehicles. The low latency andhigh bandwidth of 5G networks allow self-driving cars to communicate with each other, traffic infrastructure, and cloud-based control systems with unprecedented efficiency. Real-time data sharing enables vehicles to navigate complex environments, avoid collisions, and optimize routes, paving the way for safer and more efficient transportation systems. Moreover, 5G facilitates the development of smart cities, where interconnected traffic management systems optimize traffic flow, reduce congestion, and enhance overall mobility. While the potential benefits of 5G are undeniable, there are also challenges and concerns that must be addressed. The deployment of 5G networks requires significant investment in infrastructure, including the installation of a vast network of small cell towers to ensure adequate coverage. This infrastructure expansion raises concerns about potential environmental impacts and aesthetic considerations. Furthermore, the proliferation of interconnected devices raises concerns about data security and privacy. Ensuring the secure transmission and storage of sensitive data is paramount as 5G networks become increasingly integrated into our lives. In conclusion, 5G technology represents a paradigm shift in connectivity, offering unprecedented speed, capacity, and responsiveness. Its transformative potential extends across various sectors, revolutionizing healthcare, manufacturing, transportation, and beyond. While challenges such as infrastructure costs and data security must be addressed, the benefits of 5G far outweigh the concerns. As we embrace this new era of connectivity, it is essential to harness the power of 5G responsibly and ethically, ensuring that its benefits are shared equitably and contribute to a more connected, efficient, and sustainable future.。
雅思作文2018.1013
雅思作文2018.1013IELTS Essay: 2018.1013 The rapid advancements in technology have undoubtedly revolutionized numerous aspects of human life. However, there is an ongoing debate surrounding the overall impact of technology, with some arguing that it has made our lives easier while others contend that it has made them more complicated. This essay will delve into both sides of the argument, ultimately concluding that while technology has brought undeniable benefits, it has also introduced complexitiesthat must be carefully navigated. On the one hand, technology has undeniably simplified many aspects of daily life. Communication has been revolutionized bythe internet and smartphones, enabling instant connections across geographical boundaries. Social media platforms allow us to stay connected with friends and family regardless of distance. Online shopping platforms offer unparalleled convenience, enabling us to purchase goods and services from the comfort of our homes. Technological advancements in healthcare have led to improved diagnoses, treatments, and overall well-being. From scheduling appointments to accessing medical records, technology has streamlined the healthcare experience. Transportation has been similarly transformed, with ride-sharing apps and GPS navigation systems making travel more efficient and convenient. However, it is essential to acknowledge the complexities that technology has introduced. The overwhelming volume of information available online can lead to information overload and difficulty in discerning credible sources from misinformation. Social media, despite its ability to connect people, can also fuel social isolation and anxiety as individuals strive to portray idealized versions of themselves online. The constant connectivity fostered by smartphones can blur the boundaries between work and personal life, leading to burnout and decreased productivity. Furthermore, technological advancements in fields like artificial intelligence and automation raise concerns about job displacement and widening socioeconomic disparities. Navigating the digital world necessitates the development of new skills and literacies. Critical thinking is paramount to discerning the veracity of online information, while digital literacy is crucial for navigating the complexities of online platforms and applications. Moreover, ethical considerations must be at the forefront of technological development and implementation. Ensuring privacy anddata security is crucial in an increasingly interconnected world. Addressing the potential for algorithmic bias in areas like hiring and loan applications is essential for mitigating societal inequities. While technological advancements have undoubtedly brought immense benefits, it is crucial to approach them with a discerning eye. Embracing the advantages while mitigating the potential drawbacks necessitates a multifaceted approach. Education plays a critical role in equipping individuals with the skills and knowledge to navigate the digital landscape effectively. Fostering critical thinking, digital literacy, and ethical awareness are paramount. Furthermore, policymakers and industry leaders must proactively address concerns related to job displacement, data security, and algorithmic bias. The impact of technology on human life is multifaceted and complex. While it has simplified many aspects of our lives, it has also introduced new challenges. Ultimately, the key to harnessing the transformative power of technology lies in embracing its benefits while mitigating its potential drawbacks. By fosteringcritical thinking, digital literacy, and ethical awareness, and by addressing the societal implications of technological advancements, we can strive towards afuture where technology serves as a force for progress and betterment. In conclusion, the debate surrounding the impact of technology is likely to persistas technology continues to evolve at an unprecedented pace. However, byrecognizing both the benefits and complexities that technology presents, and by actively engaging in critical discourse and proactive solutions, we can harnessits power to create a more equitable, sustainable, and enriching future for all.。
电子信息类专业英语Unit 9 Digital Signal Processing
Unit 9 Digital Signal Processing
Figure 9.1 Analog-to-Digital Conversions
Unit 9 Digital Signal Processing
After a brief acquisition time, during which a sample is acquired, the sample and hold circuit holds the sample steady for the remainder of the sampling interval. This hold time is needed to allow time for an A/D converter to generate a digital code that best corresponds to the analog sample.
Unit 9 Digital Signal Processing
A digital signal is represented by a set of vertical lines with circles at the top to mark the quantization levels selected for each sample. The bit rate for an A/D converter is the Nfs, where fs is the sampling rate.
考研英语(一201)研究生考试2025年自测试卷与参考答案
2025年研究生考试考研英语（一201）自测试卷与参考答案一、完型填空（10分）Section I: Cloze Test (20 points)Directions: Read the following text. Choose the best word(s) for each numbered blank and mark A, B, C, or D on your answer sheet.Passage:In the world of higher education, there is an ongoing debate about the significance of standardized tests, particularly the Graduate Record Examinations (GRE) for those aspiring to pursue graduate studies. The GRE, particularly its English Language Test, known as GRE General Test (Verbal Reasoning), aims to assess a candidate’s ability to comprehend, analyze, and evaluate complex written materials. This section, specifically, the “Verbal Reasoning - Text Completion” segment, exemplifies this objective by presenting a passage with 20 blanks, each requiring a precise word or phrase to maintain the flow and meaning of the text.Text:Academic research is a meticulous process that demands not only a deep understanding of a subject matter but also the (1)_____to questionestablished knowledge and seek new perspectives. Researchers are often(2)_____with vast amounts of data, requiring them to possess excellent(3)_____skills to sift through and organize information effectively. The ability to (4)_____conclusions from such data is crucial, as it forms the basis of scientific discoveries and scholarly contributions.However, the path to research excellence is rarely (5) _____. It is fraught with challenges, including the pressure to publish in high-impact journals, the (6)_____for funding, and the constant need to innovate and stay (7)_____with the latest research trends. Despite these obstacles, researchers persevere, driven by their (8)_____to uncover the truth and make a meaningful impact on their fields.Collaboration is a cornerstone of the research process. Working together, researchers can pool their expertise, share resources, and (9)_____each other’s strengths and weaknesses. This not only accelerates the pace of research but also fosters an environment of (10)_____and mutual respect. In the realm of language and literature, researchers engage in critical analyses of texts, examining their (11)_____meaning, cultural context, and historical significance. The GRE English Test assesses this ability by testing cand idates’ comprehension of complex texts and their capacity to draw (12)_____from them. For instance, candidates may be asked to identify the author’s (13)_____or the tone of a passage, or to infer the implications of a statement made within the text.To excel in this section, candidates must develop a (14)_____vocabulary,enabling them to comprehend a wide range of vocabulary and idiomatic expressions. Additionally, honing their reading comprehension skills, such as identifying the main idea, supporting deta ils, and author’s purpose, is essential. Furthermore, the ability to (15)_____logical connections between ideas and sentences within a text is key to accurate interpretation. While preparing for the GRE, it is important to engage in regular practice, utilizing a variety of resources that mimic the actual test format. This includes working through (16)_____passages, analyzing their structure, and practicing answering questions similar to those found on the test. By doing so, candidates can (17)_____their skills and gain confidence in their abilities.Ultimately, the GRE English Test is a tool that measures a candidate’s readiness for graduate-level studies in the English language and literature. It is not a definitive measure of one’s intellectual capacity bu t rather an indication of one’s ability to navigate and excel in academic environments that prioritize (18)_____and critical thinking. As such, it is important for candidates to approach the test with a mindset focused on demonstrating their strengths and areas of improvement, rather than (19)_____on a single score.In conclusion, the GRE English Test is a challenging yet essential component of the graduate admissions process. By (20)_____a comprehensive preparation strategy that includes regular practice, vocabulary enhancement, and thedevelopment of critical reading skills, candidates can position themselves to succeed on this important milestone in their academic journey. Answers:1.courage2.confronted3.analytical4.draw5.smoothpetition7.current8.passion9.recognize10.collaboration11.literal12.inferences13.perspective14.robust15.establish16.practice17.refine18.research19.fixating20.adopting二、传统阅读理解（本部分有4大题，每大题10分，共40分）Section II: Traditional Reading ComprehensionFirst PassageTitle: The Digital Revolution and Its Impact on EducationIn the past few decades, the world has witnessed an unprecedented digital revolution that has transformed virtually every aspect of our lives. From the way we communicate to the way we access information, technology has played a pivotal role in shaping our societies. This transformation is particularly evident in the field of education, where the integration of digital tools and resources has not only revolutionized teachingmethodologies but also expanded learning opportunities for studentsglobally.The advent of the internet and the subsequent rise of online platforms have made educational resources accessible to millions of people who might not have had access to traditional educational institutions. Online courses, known as massive open online courses (MOOCs), have emerged as a popular mode of learning, offering a wide range of subjects from top universities around the world. These courses are often free or at a minimal cost, making them affordable for students from diverse economic backgrounds.Moreover, the use of digital tools in classrooms has enhanced the learningexperience for students. Interactive whiteboards, tablets, and educational software have made lessons more engaging and dynamic. Teachers can now incorporate multimedia elements such as videos, animations, and simulations into their lessons, making complex concepts easier to understand. Additionally, personalized learning programs, which utilize data analytics to tailor educational co ntent to individual students’ needs and strengths, are becoming increasingly common.However, the digital revolution in education has not been without its challenges. Concerns over digital addiction, privacy issues, and the potential for technological distractions in the classroom have been raised. Furthermore, the digital divide—the unequal distribution of access to technology and the internet—remains a significant barrier to achieving equitable education opportunities for all.Despite these challenges, the benefits of the digital revolution in education are undeniable. It has democratized access to knowledge, improved teaching and learning outcomes, and fostered innovation in educational practices. As technology continues to evolve, it is likely that the future of education will be even more deeply intertwined with digital tools and resources.Questions:1.What is the main topic of the passage?A)The rise of online shoppingB)The impact of the digital revolution on educationC)The history of the internetD)The challenges faced by traditional educational institutions2.Which of the following is NOT mentioned as a benefit of online courses?A)They are accessible to people from diverse economic backgrounds.B)They are taught by the best teachers in the world.C)They offer a wide range of subjects.D)They are often free or at a minimal cost.3.How do digital tools enhance the learning experience for students in classrooms?A)By making lessons less engaging and dynamic.B)By incorporating multimedia elements into lessons.C)By eliminating the need for teachers.D)By making it difficult to understand complex concepts.4.What is a major concern related to the digital revolution in education?A)The high cost of educational software.B)The lack of access to technology and the internet for some students.C)The excessive use of paper in classrooms.D)The decline in the quality of traditional educational institutions.5.What does the author suggest about the future of education in relation to digitaltools and resources?A)They will become less important over time.B)They will continue to play a minor role in educational practices.C)They will be completely replaced by traditional methods.D)They will become even more deeply intertwined with education.Second Section: Traditional Reading ComprehensionPassage:Title: The Impact of Digitalization on the Traditional Book IndustryIn recent years, the digital age has transformed nearly every aspect of our lives, and the book industry is no exception. With the rise of e-books, audiobooks, and digital reading platforms, the traditional paper-based model of book publishing and distribution is facing unprecedented challenges. This transformation has sparked debates among readers, authors, publishers, and librarians alike, as they grapple with the implications of this digital shift.At the heart of the matter lies the convenience offered by digital formats. E-books, for instance, can be accessed instantly on a range of devices, from smartphones to tablets, eliminating the need for physical storage space and allowing for seamless cross-device reading. They are also often cheaper than their physical counterparts, appealing to readers on a budget. Additionally, the advent of cloud storage and online libraries has made it easier than ever to access and share vast collections of books.However, these benefits come at a cost. Many argue that the digitalization of books threatens the cultural significance and physicality of the printed word. Books have traditionally served as tactile objects, conveying a sense of ownership and permanence that cannot be replicated by a screen. Moreover, the disappearance of physical bookstores has had a profound impact on communities, reducing opportunities for social interaction andbrowsing-based discovery.Authors and publishers, too, have been affected. While digital platforms have opened up new avenues for reaching readers worldwide, they have also created a crowded and competitive marketplace where visibility can be difficult to achieve. Furthermore, concerns over piracy and the loss of control over how their work is presented and distributed have led some to question the value of embracing digital formats.Yet, despite these challenges, the book industry is adapting. Publishers are exploring innovative ways to integrate digital elements into physical books, such as augmented reality and interactive features, to enhance the reading experience. Meanwhile, libraries are embracing digital resources while maintaining their physical collections, recognizing the importance of both formats for diverse user needs.Ultimately, the future of the book industry lies in a delicate balance between the traditional and the digital. As readers continue to demand convenience and accessibility, it is essential that the industry evolves to meet these needs while preserving the cultural and physical value of books.Questions:1.What is the main topic of the passage?A)The advantages of e-books over traditional books.B)The impact of digitalization on the book industry.C)The role of libraries in the digital age.D)The future of book publishing.2.What is one benefit of e-books mentioned in the passage?A)They require more physical storage space.B)They are often more expensive than physical books.C)They can be accessed instantly on various devices.D)They cannot be shared easily with others.3.According to the passage, what has been a negative impact of the decline ofphysical bookstores?A)Increased competition among publishers.B)Decreased social interaction opportunities.C)Higher prices for e-books.D)Increased piracy of books.4.How have some publishers responded to the challenges of digitalization?A)By completely abandoning physical books.B)By embracing only digital formats.C)By integrating digital elements into physical books.D)By ignoring the changing market trends.5.What is the author’s overall stance on the future of the book industry?A)It will completely shift to digital formats.B)It will maintain its traditional form without change.C)It requires a balance between the traditional and digital.D)It is impossible to predict its future trajectory.Third Question: Traditional Reading ComprehensionPassage:Title: The Digital Divide: Bridging the Gap in Access to TechnologyIn today’s rapidly evolving digital age, technology has become an integral part of our daily lives, shaping how we communicate, learn, work, and entertain ourselves. However, amidst this technological boom, a significant disparity exists –the digital divide, a term coined to describe the unequal distribution of access to, use of, or impact of information and communication technologies (ICTs) among individuals, households, businesses, and geographic areas.The digital divide manifests itself in various forms, but a primary concern lies in the gap between those who have access to the latest technological advancements and those who are left behind. This disparity can be attributed to several factors, including economic status, education levels, age, gender, and geographical location. In developing countries, the digital divide is often exacerbated by infrastructural limitations and affordability issues, while in developed nations, it may be a result of digital illiteracy or a lack of motivation to adopt new technologies. The consequences of the digital divide are far-reaching and multifaceted. On an individual level, limited access to technology can hinder educational opportunities, limit career prospects, and isolate individuals from social networks. At a societal level, it can exacerbate economic inequalities, widen the achievement gap among students, and stifle innovation and progress.Efforts to bridge the digital divide have been ongoing for years, with governments, non-profit organizations, and private companies working together to provide access to technology for those in need. Initiatives such as e-learning programs, community technology centers, and low-cost devices aim to increase digital literacy and ensure that no one is left behind in the digital age.Despite these efforts, the digital divide remains a persistent challenge. As technology continues to evolve at an unprecedented pace, it is crucial that we remain vigilant in our efforts to ensure equitable access to its benefits. Only by bridging the gap in access to technology can we ensure that everyone has the opportunity to thrive in the digital age. Questions:1.What is the digital divide, and what does it refer to?Answer: The digital divide refers to the unequal distribution of access to, use of, or impact of information and communication technologies (ICTs) among individuals, households, businesses, and geographic areas.2.What are some of the primary factors contributing to the digital divide?Answer: Some of the primary factors contributing to the digital divide include economic status, education levels, age, gender, and geographical location.3.How can limited access to technology hinder educational opportunities?Answer: Limited access to technology can hinder educational opportunities by restricting access to digital resources, such as online courses and educational software, which can be vital for learning and development.4.What are some initiatives aimed at bridging the digital divide?Answer: Some initiatives aimed at bridging the digital divide include e-learning programs, community technology centers, and low-cost devices, which aim to increase digital literacy and ensure equitable access to technology.5.Why is it important to bridge the digital divide?Answer: Bridging the digital divide is important because it ensures that everyone has equal access to the benefits of technology, which can help to reduce economic inequalities, improve educational outcomes, and foster innovation and progress. Section IV: Traditional Reading ComprehensionPassage FourTitle: The Impact of Digital Technology on Reading HabitsIn the digital age, the way we consume information has undergone a profound transformation. From the traditional paper-and-ink books to the sleek electronic screens of tablets and smartphones, the advent of digital technology has reshaped our reading habits in ways that were once unimaginable. This passage delves into the various aspects of how digitalization has influenced our reading experiences, both positively and negatively.The convenience offered by digital devices cannot be overstated. With the tap of a finger, readers can access an endless library of books, articles, and news from anywhere in the world. Gone are the days of trudging to the bookstore or waiting for a book to arrive in the mail. The instant gratification of digital reading appeals to many, especially those with busylifestyles who value time efficiency. Moreover, the ability to customize reading settings such as font size, background color, and brightness levels caters to individual preferences, enhancing the overall reading experience. However, the shift towards digital reading has also raised concerns about its impact on comprehension and retention. Some studies suggest that reading from screens can lead to decreased attention spans and reduced ability to process information deeply. The constant distractions of notifications and social media alerts can further fragment our focus, making it challenging to fully immerse oneself in a book or article. Additionally, the lack of tactile feedback from physical pages and the absence of the traditional smell and feel of a book can diminish the emotional connection readers form with the content.Moreover, the proliferation of digital content has led to an explosion of information, much of which is of questionable quality. The ease of publishing online has democratized access to the written word but has also opened the floodgates to misinformation and clickbait. Navigating through this deluge of content can be overwhelming, and readers must develop critical thinking skills to discern fact from fiction.Despite these challenges, digital technology also presents new opportunities for reading and learning. Interactive e-books, for instance, incorporate multimedia elements like videos, animations, and quizzes that can enrich the learning experience and make complex concepts more accessible.Furthermore, personalized recommendation algorithms can curate tailored reading lists based on an individual’s interests and reading history, fostering a sense of discovery and exploration.In conclusion, the impact of digital technology on reading habits is multifaceted. While it has undeniably brought about convenience and new forms of engagement, it has also raised concerns about comprehension, attention, and the quality of information available. As we continue to navigate this digital landscape, it is essential to strike a balance between embracing the benefits of technology and preserving the essence of reading as a deeply personal and enriching experience.Questions:1.What is the main advantage of digital reading mentioned in the passage?•A) The ability to access an endless library of content instantly. •B) The tactile feedback from physical pages.•C) The lack of distractions from notifications and social media. •D) The improved comprehension and retention of information.2.Which of the following is a concern raised about digital reading?•A) The enhanced emotional connection readers form with the content. •B) The increased attention spans and ability to process information deeply.•C) The decreased attention spans and reduced ability to process information deeply.•D) The limited customization options for reading settings.3.What is the primary issue with the proliferation of digital content mentioned in thepassage?•A) The lack of accessible information for readers.•B) The overabundance of high-quality content.•C) The challenge of navigating through a deluge of information, including misinformation.•D) The ease of publishing traditional books.4.How do interactive e-books contribute to the reading and learning experience?•A) By reducing the emotional connection readers form with the content. •B) By limiting access to multimedia elements like videos and animations. •C) By enriching the learning experience and making complex concepts more accessible.•D) By decreasing the convenience of digital reading.5.What is the overall message of the passage regarding the impact of digitaltechnology on reading habits?•A) Digital technology has only negative impacts on reading habits. •B) Digital technology has completely replaced traditional reading methods.•C) The impact is multifaceted, with both positive and negative aspects that require balance.•D) The benefits of digital technology far outweigh any potential drawbacks.三、阅读理解新题型（10分）Title: The Rise of E-commerce and Its Impact on Traditional RetailIn recent years, the landscape of retail has undergone a dramatictransformation, fueled primarily by the exponential growth of e-commerce.Once a niche market, online shopping has now become an integral part of consu mers’ lives, challenging the dominance of brick-and-mortar stores.This shift has far-reaching implications, reshaping not only the way we shop but also the very fabric of our economic and social structures.The Convenience Factor: At the heart of e-commer ce’s success lies its unparalleled convenience. With just a few clicks, customers can browse through a vast selection of products from the comfort of their homes, compare prices effortlessly, and have their purchases delivered right to their doorsteps. This has not only saved time but also reduced the need for physical travel, making it especially appealing to busy professionals and those living in remote areas.Access to a Global Market: Another significant advantage of e-commerce is its ability to break down geographical barriers. No longer constrained by the limitations of their local markets, businesses can now reach customers worldwide. Similarly, consumers have access to an unprecedented range of products from across the globe, often at more competitive prices than those available locally.Challenges for Traditional Retail: However, this digital revolution has notcome without its challenges for traditional retailers. The rise ofe-commerce has led to a decline in footfall at physical stores, impacting sales and profitability. To stay afloat, many retailers have had to adapt by investing in their online presence, offering click-and-collect services, and enhancing in-store experiences to attract customers.The Future of Retail: The future of retail is likely to be a blend of both online and offline experiences, with retailers leveraging technology to create seamless omnichannel strategies. Augmented reality, virtual try-ons, and personalized recommendations are just a few examples of how technology is reshaping the shopping experience. As consumers continue to embrace digital solutions, retailers must innovate and evolve to meet their changing needs.Questions:1.What is the main driver behind the transformation of the retail landscape in recentyears?A)The increasing popularity of mobile payments.B)The exponential growth of e-commerce.C)The decline of physical infrastructure.D)The introduction of new tax policies.Answer: B2.Which of the following is NOT mentioned as an advantage of e-commerce?A)The ability to compare prices easily.B)The elimination of physical travel for shopping.C)Access to exclusive products not available locally.D)The convenience of shopping from home.Answer: C3.What does the term “omnichannel strategies” refer to in the context of retail?A) A single sales channel used by retailers.B) A blend of online and offline shopping experiences.C) A marketing technique focused on social media.D) A strategy to reduce operating costs.Answer: B4.How has the rise of e-commerce impacted traditional retailers?A)It has led to an increase in their sales and profitability.B)It has made them more competitive in the global market.C)It has caused a decline in footfall at their physical stores.D)It has made them completely obsolete in the retail industry.Answer: C5.Which technology is mentioned as having the potential to reshape the shoppingexperience?A)Artificial Intelligence.B)Augmented Reality.C)Internet of Things.D)Blockchain.Answer: B四、翻译（本大题有5小题，每小题2分，共10分）First QuestionQuestion: Translate the following paragraph into Chinese:The digital era has revolutionized the way we interact with information, making it possible to access vast amounts of knowledge instantly from anywhere in the world. This paradigm shift has not only altered our personal lives but also transformed industries, businesses, and the very fabric of society. As individuals navigate this ever-evolving landscape, it becomes increasingly crucial to develop a strong sense of digital literacy, enabling us to critically evaluate information, protect our privacy, and harness the power of technology for positive outcomes.Answer:数字时代彻底改变了我们与信息互动的方式，使我们能够瞬间从世界任何地方获取大量知识。
理性使用数字技术作文
理性使用数字技术作文英文回答：The advent of digital technologies has revolutionized our lives, providing us with unprecedented access to information, communication, and entertainment. While these technologies offer numerous benefits, it is crucial to use them rationally to maximize their positive impact and minimize potential risks.First and foremost, it is important to approach digital technologies with a critical mindset. We must be mindful of the information we consume and the sources from which it comes. With the proliferation of fake news and misinformation, it is more important than ever to verify information before sharing or believing it. This involves checking multiple sources, considering the credibility of authors, and being aware of our own biases.Furthermore, we should be mindful of the amount of timewe spend using digital devices. Excessive screen time can lead to a variety of health issues, including eye strain, sleep problems, and social isolation. It is essential to set limits on our digital usage and make sure to engage in other activities that promote our physical and mental well-being.Another important aspect of rational digital use is protecting our privacy and personal data. Digital technologies collect vast amounts of information about our online activities, which can be used for various purposes, including targeted advertising, surveillance, and even discrimination. We should take steps to protect our privacy by using strong passwords, being cautious about the information we share online, and using privacy-enhancing tools.In the workplace, it is essential to use digital technologies effectively and efficiently. This involves understanding the capabilities of various tools and software, as well as managing our time wisely to avoid burnout. It is also important to maintain a healthy work-life balance and avoid excessive use of digitaltechnologies outside of work hours.Finally, we must consider the ethical implications of digital technologies. These technologies have the potential to be used for both good and evil, and it is up to us to ensure that they are used in a responsible and ethical manner. This includes using digital technologies to promote social justice, fight discrimination, and address environmental challenges.中文回答：理性使用数字技术。
2025年全国大学英语CET四级考试试卷及答案指导
2025年全国大学英语CET四级考试模拟试卷及答案指导一、写作（15分）WritingTask: For this part, you are allowed 30 minutes to write a short essay on the topic “The Importance of Reading in Life.” You should write at least 120 words but no more than 180 words. You should base your essay on the outline given below:1.Introduce the significance of reading in daily life.2.Discuss the benefits of reading, such as expanding vocabulary, improving writing skills, and enhancing knowledge.3.Conclude by expressing your personal views on the importance of reading.Example:Reading: The Key to a Wealthy MindIn today’s fast-paced world, reading has become an essential part of daily life. It is not merely a hobby but a crucial tool for personal and professional growth.Firstly, reading greatly expands one’s vocabulary. By encountering new words and phrases in various contexts, individuals can enrich their languageskills and express themselves more effectively. Moreover, reading improves writing skills by providing examples of good sentence structure and persuasive arguments.Secondly, reading broadens one’s knowledge. Whether it’s through novels, non-fiction books, or articles, reading exposes us to different cultures, ideas, and perspectives. This not only fosters critical thinking but also helps us understand the world around us better.In conclusion, reading is an invaluable activity that enriches our minds and enhances our lives. It is through reading that we can continue to grow, learn, and adapt to the ever-changing world. As such, I firmly believe that reading should be a lifelong pursuit.Analysis:This example essay effectively addresses the topic by following the given outline. The introduction clearly states the significance of reading in daily life. The body paragraphs then discuss the benefits of reading, with the first paragraph focusing on vocabulary expansion and the second on knowledge enhancement. The conclusion summarizes the essay’s main points and reinforces the importance of reading.The essay demonstrates a good command of language, with a variety of sentence structures and appropriate vocabulary usage. It also maintains a coherent flow of ideas, making it easy for the reader to follow the aut hor’s argument.二、听力理解-短篇新闻（选择题，共7分）第一题Passage OneNews Item 1:A new study reveals that the number of people working from home has doubled in the past year due to the COVID-19 pandemic. Many companies have embraced remote work as a way to reduce costs and improve employee satisfaction. However, experts warn that this trend may lead to increased mental health issues among workers. The study suggests that employers should provide support systems to help employees manage the challenges of working from home.Questions:1、What is the main topic of the news item?A) The benefits of working from home.B) The challenges of working from home.C) The increase in remote work during the pandemic.D) The impact of remote work on mental health.2、Why have many companies embraced remote work?A) To reduce costs.B) To improve employee satisfaction.C) Both A and B.D) To address the COVID-19 pandemic.3、What is the concern expressed by experts regarding the trend of workingfrom home?A) It may lead to a decrease in employee satisfaction.B) It may increase mental health issues among workers.C) It may cause a decline in productivity.D) It may lead to more workplace accidents.Answers:1、C2、C3、B第二题News Item 1:A new study has shown that consuming green tea may help reduce the risk of developing Parkinson’s disease. Researchers at the University of California, Los Angeles, found that compounds in green tea called polyphenols can protect brain cells from the damage caused by toxins. The study followed over 1,000 individuals over a period of 10 years. Those who consumed green tea regularly were 50% less likely to develop Parkinson’s disease than those who did not.Questions:1、What is the main finding of the study conducted at the University of California, Los Angeles?A) Green tea can completely cure Parkinson’s disease.B) Regular consumption of green tea may reduce the risk of developingParkinson’s disease.C) Only those who drink green tea are at risk of develop ing Parkinson’s disease.D) Polyphenols in green tea are harmful to brain cells.2、How long did the study follow the participants?A) 5 yearsB) 7 yearsC) 10 yearsD) 12 years3、According to the study, what percentage reduction in the risk of developing P arkinson’s disease was observed in regular green tea consumers compared to non-consumers?A) 20%B) 30%C) 40%D) 50%Answers:1、B) Regular consumption of green tea may reduce the risk of developing Parkinson’s disease.2、C) 10 years3、D) 50%三、听力理解-长对话（选择题，共8分）第一题听力原文：A. Man: Hey, are you ready for the CET-4 exam?B. Woman: Yeah, I’ve been studying really hard for the past few months.I think I’m ready.A. Man: That’s good to hear. Do you have any tips for the listening section?B. Woman: Well, I would say practice is key. Listen to English news, watch English movies, and try to understand the conversations.A. Man: And what about the reading section?B. Woman: I would focus on reading a variety of materials like newspapers, magazines, and online article s. It’s important to get used to different styles of writing.A. Man: I see. And what about the writing section?B. Woman: For the writing section, I would recommend practicing writing essays on different topics. It’s also important to check your grammar and punctuation.A. Man: That makes sense. I’m going to do the same thing. Good luck!B. Woman: Thanks, and good luck to you too!选择题：1、What are the speakers mainly discussing?A. Preparation for the CET-4 examB. Different sections of the CET-4 examC. Tips for improving English listening skillsD. The importance of practice for the CET-4 exam2、What does the woman say about the listening section?A. She suggests focusing on reading materials.B. She thinks it’s important to practice listening to English news.C. She recommends studying grammar for the listening section.D. She suggests practicing writing essays for the listening section.3、What does the woman say about the reading section?A. She believes it’s important to study grammar for the reading section.B. She thinks it’s important to practice listening to English news.C. She recommends focusing on a variety of reading materials.D. She suggests practicing writing essays for the reading section.4、What does the woman suggest for the writing section?A. She recommends studying grammar for the writing section.B. She thinks it’s important to practice listening to English news.C. She suggests focusing on a variety of reading materials.D. She recommends practicing writing essays on different topics.答案：1、A2、B3、C4、D第二题Listen to the following conversation and answer the questions.W: Hi, John. How was your weekend?M: Oh, it was great. I decided to take a trip to the countryside. I went to visit an old friend who lives there.W: That sounds nice. Did you do anything specific?M: Yes, we went for a hike in the mountains. It was beautiful. We also stopped by a small village for lunch.W: Did you try any local dishes?M: Absolutely. We had this delicious chicken dish with potatoes and vegetables. It was so flavorful.W: That sounds amazing. How long did you stay?M: We spent the whole day there. We didn’t leave until evening. It was a perfect getaway.W: I wish I could go somewhere like that. What did you do when you got back?M: I just relaxed and took a nice, long shower. I was exhausted from all the walking.W: Sounds like a good way to unwind. Do you think you’ll go back anytime soon?M: I think so. My friend and I are planning another trip next month.1.What did the man do over the weekend?A) He stayed home.B) He visited a friend in the countryside.C) He went to the beach.D) He had a staycation.2.Why did the man go to the countryside?A) To see a family member.B) To attend a conference.C) To go hiking.D) To visit a museum.3.What did the man and his friend do while in the countryside?A) They watched a movie.B) They went shopping.C) They went for a hike.D) They had a picnic.4.What did the man say about the local food?A) It was too spicy.B) It was not as good as he expected.C) It was delicious and flavorful.D) It was too expensive.Answers:1.B) He visited a friend in the countryside.2.C) They went for a hike.3.C) They went for a hike.4.C) It was delicious and flavorful.四、听力理解-听力篇章（选择题，共20分）第一题听力篇章Passage OneQuestions 1 to 5 are based on the following passage.American football, originally a college game, was introduced into the United States by Walter Camp, who is called the “Father of American Football.” Camp was a coach at Yale University, and he is known as the man who invented the system of numbering the players on the field. The game was originally played by using a soccer ball. Camp suggested that a ball resembling a prolate spheroid (椭球体) be used. This ball is rounder than a soccer ball and is used in American football today.The rules of the game were also established by Camp. He divided the field into two sections, with the goal line in the center. The game was played with a single ball, and each team tried to carry the ball across the opponent’s goal line. The first team to do so would win the game. Camp also introduced the concept of tackling, which is the act of tackling an opponent to the ground. This is still a fundamental part of the game today.Over the years, American football has become a professional sport, with teams competing in the National Football League (NFL). The NFL is the most popular professional football league in the United States. The game is also played in high schools and colleges across the country.1、What is Walter Camp known for in American football?A)、Being the founder of the NFL.B)、Inventing the system of numbering players on the field.C)、Introducing the game to the United States.D)、Establishing the rules of the game.2、What did Camp suggest as a replacement for the soccer ball in the early days of American football?A)、A ball with a square shape.B)、A ball resembling a prolate spheroid.C)、A ball with a flat surface.D)、A ball with a hole in the center.3、According to the passage, what is the main objective of each team in an American football game?A)、To score points by carrying the ball across the opponent’s goal line.B)、To tackle the opponent’s players to the ground.C)、To win the game by scoring the most points.D)、To pass the ball to the opponent’s team.第二题PassageIn recent years, the concept of “slow living” has gained significant attention around the world. This movement encourages people to slow down their pace of life and appreciate the present moment. One of the key principles ofslow living is the emphasis on local and sustainable consumption.The fast-paced modern world has led to increased stress, anxiety, and a sense of being overwhelmed. Many people feel that they are constantly chasing after time, and they often forget to take care of their physical and mental health. Slow living advocates believe that by reducing the pace of life, individuals can achieve a better work-life balance and lead a more fulfilling life.One way to practice slow living is by supporting local businesses and consuming locally produced goods. This not only helps to strengthen the local economy but also reduces the carbon footprint associated with long-distance transportation. For example, buying fresh produce from local farmers’ markets not only supports local agriculture but also ensures that the food is fresh and nutritious.Moreover, slow living encourages people to connect with others and build strong communities. Activities such as cooking together, sharing meals, and engaging in community service are all part of the slow living philosophy. These activities foster a sense of belonging and reduce social isolation.However, the transition to slow living can be challenging. It requires a conscious effort to change habits and prioritize experiences over material possessions. It also means being more mindful of one’s consumption and making sustainable choices.Questions:1、What is the main idea of the passage?A) The benefits of fast livingB) The importance of consuming locally produced goodsC) The concept and principles of slow livingD) The challenges of practicing slow living2、According to the passage, what is one of the positive effects of slow living?A) Increased stress and anxietyB) A better work-life balanceC) Higher levels of social isolationD) Less appreciation for the present moment3、Why is supporting local businesses important in the context of slow living?A) It helps to reduce the carbon footprint of long-distance transportationB) It encourages people to consume more material possessionsC) It promotes global economic dominanceD) It leads to the decline of local agricultureAnswers:1、C2、B3、A第三题Passage OneWhen it comes to working with animals, you might think of a veterinarian,a person who treats sick animals. But in the United States, some people work with animals without treating them. They train them to do certain things. These people are known as animal trainers.The work of an animal trainer can be difficult. Not all animals are willing to do what they are asked. Sometimes, a trainer has to work for hours without getting any results. But when an animal finally performs a task correctly, the trainer feels a great sense of satisfaction.Many animal trainers work with animals that perform in shows. These animals might be seen in circuses, zoos, or on television. They can also be seen in commercials. Animal trainers work with many different kinds of animals. Some work with dogs, cats, and other pets. Others work with animals that are not pets, such as horses, dolphins, and even bears.Animal trainers use different methods to train animals. They use positive reinforcement, which means that they reward an animal when it does something right. They also use negative reinforcement, which means that they punish an animal when it does something wrong. Some trainers use a combination of both methods.Training animals can be dangerous. A trainer might be bitten or scratched by an animal. Even when an animal seems friendly, it can still be unpredictable. That’s why animal trainers must be careful and patient.Questions:1、What is the main purpose of the passage?A. To describe the difficulties faced by animal trainers.B. To explain the different methods used by animal trainers.C. To discuss the various types of animals that animal trainers work with.D. To introduce the concept of animal trainers and their work.2、According to the passage, how do animal trainers feel when an animal finally performs a task correctly?A. DisappointedB. AnnoyedC. SatisfiedD. Bored3、What is one potential danger associated with being an animal trainer?A. Being late for workB. Not getting enough sleepC. Being bitten or scratched by an animalD. Forgetting to feed the animalsAnswers:1、D2、C3、C五、阅读理解-词汇理解（填空题，共5分）第一题Read the following passage and then answer the questions by choosing the most suitable word for each blank from the four choices given below.In the fast-paced modern world, technology has become an indispensable part of our daily lives. It has revolutionized the way we communicate, work, and even how we interact with others. One of the most significant advancements in technology is the internet, which has transformed the way we access information and connect with people from all over the world.However, despite its numerous benefits, technology also poses several challenges. One of the most pressing issues is the impact it has on our mental health. Excessive use of smartphones and other electronic devices can lead to problems such as anxiety, depression, and sleep disorders. Additionally, the internet has made it easier for people to become victims of cyberbullying and online scams.1、It is crucial to maintain a balance between technology and our personal lives to ensure a healthy lifestyle.2、The internet has made it easier for people to access information, but it has also increased the risk of falling victim to online scams.3、Excessive use of smartphones and other electronic devices can have severe consequences for our mental health.4、In today’s world, technology has become an integral part of our daily lives.5、One of the challenges of technology is the negative impact it can haveon our mental well-being.A. indispensableB. revolutionizeC. accessD. cyberbullyingE. indispensableF. revolutionizeG. accessH. cyberbullying答案1、A2、H3、D4、E5、B第二题Reading PassageAs the world becomes increasingly interconnected, the importance of cultural competence has become more pronounced. Cultural competence refers to the ability to understand, appreciate, and interact effectively with people from different cultural ba ckgrounds. This skill is particularly valuable in today’s globalized economy, where companies and organizations are more likely to work with international partners and clients.One key aspect of cultural competence is the ability to communicate effectively across cultures. This involves not only understanding the linguistic differences but also being aware of the non-verbal cues and social norms that vary from one culture to another. For example, a high-context culture, like Japan, relies heavily on non-verbal communication and indirect communication, while a low-context culture, like the United States, tends to value direct and explicit communication.The following passage contains vocabulary that may be new to you. Choose the most appropriate word from the list below to complete each sentence. Thereare more words than sentences, so there will be some extra words. Do not use any of the words more than once.Vocabulary List:1.Acculturation2.Cohesion3.Diversify4.Harmony5.Integration6.Intricate7.Mnemonic8.Paradoxical9.Proliferate10.SynergySentences:1、The company has decided to__________their workforce to better represent the diversity of their client base.2、After years of living abroad, she felt a sense of__________with her new culture.3、The manager emphasized the importance of cultural__________in order to foster a positive work environment.4、The museum exhibit showcased the__________designs of various civilizations throughout history.5、To remember the names of all the new employees, he used a__________device to create memorable associations.Answers:1.Diversify2.Acculturation3.Cohesion4.Intricate5.Mnemonic六、阅读理解-长篇阅读（选择题，共10分）第一题Reading Passage OneIn recent years, there has been a growing concern about the impact of social media on young people’s mental health. While social media platforms offer numerous benefits, such as connectivity and access to information, they also pose significant risks to the mental well-being of users, especially teenagers. This passage explores the effects of social media on young people’s mental health and discusses potential solutions to mitigate these risks.Paragraph 1Social media has become an integral part of daily life for many young people. Platforms like Instagram, Facebook, and Twitter allow teenagers to connect with friends, share experiences, and express themselves. However, this constantexposure to the curated lives of others can lead to feelings of inadequacy, anxiety, and depression.Questions:1、What is the main concern expressed in the first paragraph?A. The benefits of social media.B. The risks of social media.C. The impact of social media on daily life.D. The role of social media in teenagers’ lives.2、According to the passage, which of the following is a potential negative effect of social media on young people’s mental health?A. Increased self-esteem.B. Enhanced social skills.C. Reduced feelings of inadequacy.D. Heightened anxiety and depression.Paragraph 2Research has shown that excessive use of social media can lead to sleep disturbances, as teenagers spend more time on their devices rather than getting enough rest. Additionally, the constant need for validation and approval from peers can contribute to feelings of low self-worth and anxiety.Questions:3、What is one consequence of excessive social media use mentioned in the second paragraph?A. Improved sleep quality.B. Increased self-worth.C. Reduced anxiety.D. Sleep disturbances.4、Which of the following is NOT mentioned as a potential negative effect of social media use on mental health?A. Anxiety.B. Depression.C. Improved social skills.D. Sleep disturbances.Paragraph 3To address these issues, some experts suggest implementing stricter regulations on social media platforms, such as age restrictions and content filtering. Others argue that parents and educators should play a more active role in monitoring and guiding youn g people’s use of social media.Questions:5、What measures are suggested to mitigate the negative effects of social media on young people’s mental health?A. Implementing stricter regulations on social media platforms.B. Encouraging young people to use social media more frequently.C. Reducing the amount of time spent on social media.D. Ignoring the potential risks of social media.Answers:1、B2、D3、D4、C5、A第二题Reading Time: 40 minutesDirections: For this part, you are allowed 40 minutes to read a long passage and answer the questions on it. You should write your answers on the Answer Sheet.Passage:In the digital age, the way we communicate has undergone a remarkable transformation. With the advent of the internet and various digital platforms, the traditional methods of communication such as postal mail and landline phones have become less prominent. One of the most influential digital communication tools is social media. Platforms like Facebook, Twitter, and Instagram have revolutionized the way people connect and share information. However, along with these advancements come challenges and concerns.1、The first challenge of digital communication is the potential for misinterpretation. Without the nuances of face-to-face communication,text-based messages can be easily misunderstood. This can lead to misunderstandings, conflicts, and even legal disputes.2、Another significant challenge is the issue of privacy. With the vast amount of p ersonal data being shared online, individuals’ privacy is at risk. Cybersecurity breaches have become increasingly common, and the consequences can be severe, ranging from identity theft to financial loss.3、Despite these challenges, digital communication offers numerous benefits. It allows people to connect with others across the globe instantaneously. This has facilitated international collaborations, business partnerships, and cultural exchanges. Additionally, digital communication is cost-effective and time-efficient.4、However, there are concerns about the impact of digital communication on face-to-face interactions. Some argue that excessive reliance on digital communication leads to a decline in interpersonal skills and the ability to engage in meaningful conversations.5、The following questions are based on the passage above.Questions:1、What is the main challenge of digital communication mentioned in the passage?A) Lack of face-to-face interactionB) Potential for misinterpretationC) High cost of communicationD) Difficulty in maintaining privacy2、Which of the following is NOT a challenge of digital communicationaccording to the passage?A) Privacy issuesB) Instantaneous connection with people worldwideC) Decline in interpersonal skillsD) Cybersecurity breaches3、What benefit of digital communication is mentioned in the passage?A) Increased risk of legal disputesB) Cost-effectiveness and time efficiencyC) Decline in face-to-face interactionsD) Enhanced cybersecurity4、What concern is raised about the impact of digital communication on face-to-face interactions?A) It leads to a decrease in the ability to engage in meaningful conversations.B) It increases the risk of cybersecurity breaches.C) It causes a decline in interpersonal skills.D) It leads to misunderstandings and conflicts.5、Which of the following is a positive aspect of digital communication mentioned in the passage?A) Increased risk of legal disputesB) Cost-effectiveness and time efficiencyC) Decline in interpersonal skillsD) Difficulty in maintaining privacyAnswers:1、B2、B3、B4、A5、B七、阅读理解-仔细阅读（选择题，共20分）第一题Reading Passage 1Questions 1 to 5 are based on the following passage.The digital revolution has transformed the way we live, work, and communicate. One of the most significant impacts has been on education. Online learning platforms, virtual classrooms, and educational apps have become increasingly popular, offering new opportunities for students and educators alike.In many countries, traditional classrooms are being augmented with digital tools and resources. Teachers are incorporating interactive whiteboards, tablets, and educational software into their lessons to enhance student engagement and understanding. This integration of technology has led to a more dynamic and engaging learning environment.However, the digital transformation of education also raises concerns aboutits impact on students’ social skills and mental health. Some argue that excessive reliance on digital devices can lead to isolation and anxiety, especially for younger students who are still developing their social and emotional abilities.Despite these concerns, the benefits of digital education are undeniable. Online learning platforms provide access to a vast array of resources that can supplement traditional classroom teaching. Students can access educational materials from around the world, engage in collaborative projects with peers, and receive personalized learning experiences tailored to their individual needs.1、What is one of the significant impacts of the digital revolution on education?A. Increased access to educational resources.B. Improved social skills among students.C. Reduction in teacher workload.D. Enhanced classroom engagement.2、How are digital tools and resources being used in traditional classrooms?A. To replace textbooks and traditional teaching methods.B. To augment existing teaching methods and enhance engagement.C. To reduce the number of students in each classroom.D. To provide students with more time for independent study.3、What is a concern raised about the digital transformation of education?A. The increase in the number of educational apps available.B. The potential negative impact on students’ social skills and mental health.C. The reduction in the quality of classroom instruction.D. The loss of interest in traditional learning methods.4、What is one of the benefits of online learning platforms?A. They require students to work independently at all times.B. They limit studen ts’ access to educational materials from other countries.C. They provide personalized learning experiences for each student.D. They are only useful for students who are already highly motivated to learn.5、How does the passage describe the role of digital tools and resources in education?A. They are a complete replacement for traditional teaching methods.B. They are being used to supplement and enhance traditional teaching methods.C. They are only beneficial for students who have access to advanced technology.D. They are being used to reduce the number of students in each classroom.Answers:1、A. Increased access to educational resources.。
笛卡尔网格生成中的相交算法
笛卡尔网格生成中的相交算法作者：张立何冰封卫兵张武来源：《计算机辅助工程》2013年第01期摘要：研究三维空间笛卡尔网格与三角形面网格的相交判断算法——ADT（Alternating Digital Tree）算法和KD（KDimensional）树算法，分别用球体模型和飞机模型对ADT与KD 树进行分析，比较二者快速相交判断时的查找效率.结果表明：同一种模型下ADT比KD树平衡，树的深度小；ADT的查找效率明显比KD树高；影响KD树查找时间的主要因素是查找次数.整体来看，在快速相交判断中采用ADT性能更高.关键词：笛卡尔网格；三角形面网格；体网格；格子Boltzmann方法； ADT； KD树；相交算法；查找效率中图分类号： O241.82；O35文献标志码： B引言基于Boltzmann方程的LBM（Lattice Boltzmann Method）[12]方法是当今CFD研究的热点之一.LBM是近年来发展起来的一种求解偏微分方程的数值方法，在CFD领域中的应用已与传统的有限差分法、有限体积法和有限元法等数值计算方法并驾齐驱.与传统的数值解法不同的是，LBM从系统的微观模型出发，根据系统的微观行为设计LBM的演化方程，使模型的宏观方程与描述系统宏观行为的偏微分方程保持一致，从而在对系统进行模拟的同时，实现对偏微分方程的数值求解.由于LBM具有计算效率高、边界条件容易实现和完全并行性等优势，吸引众多领域中的学者和工程技术人员.目前，LBM已在多相流、多孔介质流、悬浮粒子流、反应流、磁流体力学和生物力学等领域取得很大成功，其高效、精确和健壮性已得到广泛证实.[1]与传统的数值求解方法相同，LBM解决实际问题的步骤包括前处理、计算和后处理等几个部分.在前处理过程中，网格划分的好坏直接关系到计算结果的精度和正确与否，是数值求解的关键步骤.因此，计算网格生成受到世界各国计算者和工业部门的重视.网格生成方法众多，其中笛卡尔网格是CFD计算中最早使用，也是最容易生成的一种网格.不同于传统的贴体网格，笛卡尔网格中的单元基本按照笛卡尔坐标方向（x，y，z）排列.笛卡尔网格生成时，首先将需要计算的流场取成长方体，并对计算区域进行调整；再对其进行均匀划分，生成初始化网格，使得每个网格均为立方体；然后判断每个网格与物面的相交情况并对相交的体网格进行标记；最后对标记的体网格进行自适应局部加密，产生适宜的网格.由于笛卡尔网格不用考虑部件之间的相互关系，可以一次生成所需的计算网格，简单、省时，而且笛卡尔网格在流场计算中实现自适应比较简单、容易，因此网格生成过程不需要人为干预，节省前处理的时间.[3]1问题描述判断与某个体网格可能相交的面网格的过程称为快速相交判断.[4]在计算流体力学中，构成几何体的面网格以及体网格的数量比较多，若遍历所有面网格并判断是否与体网格相交，所需时间较长.因此，可以先求与体网格可能相交的面网格，去掉大部分不相交的网格，然后对所求得的可能相交的网格进行精确相交判断.这与复杂游戏场景中的碰撞检测策略相同：先快速排除明显不发生碰撞的物体，确定可能的相交元素，减少精确相交判断时需要判断的元素个数.本文的物面网格是Delaunay网格，为方便求解，将面网格与体网格的相交判断转换为2个长方体之间的相交判断.因此，在求相交之前必须确定每个面网格对应的包围盒大小，然后将面网格插入到二叉树中，判断二叉树节点处的面网格是否与体网格相交.用于存储面网格的二叉树有多种，如AABB树，ADT （Alternating Digital Tree）[45]和KD（KDimensional）树[6]等，本文主要研究ADT和KD树.在文献[3]，[4]，[7]和[8]中都采用ADT存储面网格，缩短网格与物面相交判断的时间.2快速相交算法。
浙江省宁波市九校2023-2024学年高二下学期期末联考英语试题(含答案)
宁波九校高二期末考英语试题第一部分：听力（共两节，满分30分）做题时，先将答案标在试卷上。
录音内容结束后，你将有两分钟的时间将试卷上的答案转涂到答题纸上。
第一节：（共5小题；每小题1.5分，满分7.5分）听下面5段对话。
每段对话后有一个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。
听完每段对话后，你都有10秒钟的时间来回答有关小题和阅读下一小题。
每段对话仅读一遍。
1.What can people do in Moon Bay Mall?A.Play the guitar.B. Ride skateboards.C. Shop with their pets.2.Who is the woman?A.A patient.B.A nurse.C.A doctor.3.How does the man help the woman?A.By fixing her bike at a low price.B.By calling the repair shop for her.C.By recommending a repair shop to her.4.Where will the woman go?A. The French market.B. The Canadian market.C. The Australian market.5.What does the man mean?A.He is energetic in working.B.He doesn’t like his job.C.He is tired of traveling.第二节：（共15小题；每小题1.5分，满分22.5分）听下面5段对话或独白。
每段对话或独白后有几个小题，从题中所给的A、B、C三个选项中选出最佳选项。
听每段对话或独白前，你将有时间阅读各个小题，每小题5秒钟；听完后，各小题将给出5秒钟的作答时间。
数字技术是把双刃剑作文
数字技术是把双刃剑作文英文回答：The advent of digital technology has brought about a transformative era, profoundly shaping our lives in myriad ways. While it has undoubtedly conferred numerous benefits, it also presents a formidable double-edged sword, necessitating a critical examination of its implications.Connectivity and Communication:Digital technology has shattered geographical barriers, facilitating seamless communication and fostering global interconnectedness. Social media platforms, instant messaging applications, and video conferencing tools have bridged the gaps between individuals and communities, enabling them to connect with each other instantaneously and effortlessly. The proliferation of online learning resources and MOOCs (Massive Open Online Courses) has empowered individuals from all walks of life to pursueeducational opportunities that were previously inaccessible.However, this ease of connectivity may also foster a sense of isolation and detachment. The constant bombardment of information and the allure of virtual interactions can lead to individuals withdrawing from real-world relationships. Moreover, the rise of "filter bubbles" and echo chambers on social media platforms can contribute to polarization and the spread of misinformation.Convenience and Automation:Digital technology has revolutionized the way we access goods and services. Online shopping, e-banking, and home automation systems have made our lives more convenient and efficient. Artificial intelligence (AI) and machinelearning algorithms automate repetitive tasks, freeing up human time for more creative and fulfilling endeavors.Yet, the overreliance on automation may result in job displacement and exacerbate socioeconomic inequalities. As machines become more sophisticated, certain professions maybecome obsolete, leading to unemployment and financial hardship. Additionally, the use of AI in decision-making processes raises ethical concerns, as algorithms may perpetuate bias and reinforce existing power structures.Access to Information and Knowledge:The internet has become an unparalleled reservoir of information, empowering individuals with unprecedented access to knowledge and perspectives. Search engines, online encyclopedias, and digital libraries provide a wealth of educational materials and research resources that were once limited to libraries and academic institutions.However, the democratization of information also poses challenges. The sheer volume of information online can be overwhelming, and it requires critical thinking skills to discern credible sources from unreliable ones. Moreover, the spread of misinformation and disinformation can sow seeds of doubt and erode trust in institutions and experts.Health and Well-being:Digital technology has made significant contributions to the advancement of healthcare. Wearable devices and smartphone applications track health metrics, promote physical activity, and provide access to telemedicine services. Electronic health records streamline communication between patients and healthcare providers, improving the quality and efficiency of care.Conversely, excessive screen time can lead to physical and mental health issues. Prolonged exposure to blue light emitted from digital devices can disrupt sleep patterns and cause eye strain. Furthermore, the addictive nature of social media and gaming platforms can lead to sedentary lifestyles and mental health concerns, such as anxiety and depression.Conclusion:Digital technology is an indispensable tool that has transformed our lives in countless ways. However, it is essential to recognize its dual nature and to navigate itscomplexities with prudence. By embracing the benefits while mitigating the potential risks, we can harness the power of technology to create a more equitable, sustainable, and fulfilling future for all.中文回答：数字化技术是一把双刃剑。
用数字之光,开启希望之门的作文
用数字之光,开启希望之门的作文英文回答：The dawn of the digital age has brought with it a beacon of hope, casting its luminous rays upon the gates of human potential. The proliferation of technology has empowered us to unlock doors that were once deemed inaccessible, illuminating pathways towards a brighter and more fulfilling future.Like the celestial bodies that guide mariners across treacherous waters, numbers have emerged as guiding lights in our contemporary world. They have become the language of innovation, enabling us to decipher complex algorithms, unravel the mysteries of the universe, and probe the depths of our own consciousness.Through the manipulation of numbers, we have devised intricate machines that perform tasks beyond human capabilities, from self-driving cars to artificialintelligence. These technological marvels have transformed industries, improved our quality of life, and expanded our understanding of the world.Moreover, numbers have become indispensable in the pursuit of scientific knowledge. They allow us to quantify and analyze data, test hypotheses, and draw informed conclusions about the natural world. Through statistical models and complex equations, scientists have unlocked the secrets of the human genome, discovered distant planets, and predicted the trajectory of our climate.But the transformative power of numbers extends beyond the realm of science and technology. In the arts, they serve as a medium for expression, allowing artists to convey emotions, ideas, and stories in a unique and compelling way. Musical compositions are woven together from intricate combinations of notes and rhythms, while visual artists use numbers to create geometric patterns and abstract forms.Furthermore, numbers have become an integral part ofour social and economic fabric. They are used to measure economic growth, track population trends, and facilitate international trade. Through the development of sophisticated financial models, we have created complex systems that govern the flow of capital and investment.However, the unlocking of hope's gates through digital light is not without its challenges. The rapid pace of technological advancement can be daunting, creating a digital divide between those who have access to the necessary tools and knowledge and those who do not. It is imperative that we bridge this gap and ensure that everyone has the opportunity to participate in the digital revolution.Moreover, we must be mindful of the potential ethical implications of our digital advancements. As we rely increasingly on algorithms and artificial intelligence to make decisions, it is crucial that we develop safeguards to prevent bias, discrimination, and unintended consequences.中文回答：数字之光，开启希望之门。
digital divide英语作文真题
digital divide英语作文真题全文共3篇示例，供读者参考篇1The digital divide is a term that refers to the gap between those who have access to digital technologies and those who do not. This divide can exist both within countries and between countries, and it has the potential to create significant inequalities in areas such as education, employment, and healthcare.One of the key factors contributing to the digital divide is the availability of internet access. In many developed countries, access to the internet is nearly universal, with high-speed connections available in most urban areas. However, in many developing countries, internet access is limited to a small percentage of the population, often due to a lack of infrastructure or high costs. This lack of access can havefar-reaching consequences, as the internet is increasingly becoming a vital tool for communication, education, and economic development.Another factor contributing to the digital divide is the availability of digital devices. In many developed countries, smartphones, tablets, and computers are ubiquitous, and most people have access to these devices in their homes or schools. However, in many developing countries, these devices are still out of reach for the majority of the population, leading to a lack of digital literacy and skills that are becoming increasingly important in today's digital world.The consequences of the digital divide are numerous and far-reaching. In terms of education, students who do not have access to digital technologies may be at a disadvantage compared to their peers who do. Online learning platforms and resources are becoming increasingly important in education, and students without access to these tools may struggle to keep up with their studies. This can lead to lower educational outcomes and fewer opportunities for success in the future.In terms of employment, the digital divide can create barriers for those who do not have access to digital technologies. Many jobs now require at least basic digital skills, such as the ability to use email, search the internet, and use basic office software. Those without these skills may find themselves limitedto lower-paying and less secure jobs, perpetuating the cycle of poverty and inequality.In terms of healthcare, the digital divide can also have serious consequences. Telemedicine, or the use of digital technologies to provide medical care remotely, is becoming increasingly common in many parts of the world. However, those without access to the internet or digital devices may not be able to take advantage of this technology, leading to limited access to medical care and poorer health outcomes.In order to bridge the digital divide, a multi-faceted approach is needed. This approach should include efforts to improve internet infrastructure in underserved areas, reduce the cost of internet access, and provide digital devices to those who cannot afford them. In addition, efforts should be made to provide digital literacy training to those who lack basic digital skills, in order to ensure that everyone has the tools they need to succeed in today's digital world.Overall, the digital divide is a significant challenge that must be addressed in order to create a more equitable and inclusive society. By working together to bridge this gap, we can ensure that everyone has access to the tools they need to succeed in today's digital world.篇2The digital divide refers to the gap between people who have access to digital technologies and those who do not. This divide is a serious issue in today's society as technology plays a crucial role in almost every aspect of our lives. In this essay, we will explore the causes and consequences of the digital divide, as well as possible solutions to address this issue.One of the main causes of the digital divide is socioeconomic factors. People from lower-income households are less likely to have access to digital technologies such as computers and the internet. This lack of access can put them at a disadvantage in terms of education, job opportunities, and even healthcare. In addition, rural areas often have limited access to high-speed internet, further widening the digital divide between urban and rural communities.Another factor contributing to the digital divide is the lack of digital literacy. Even if people have access to technology, they may not have the skills or knowledge to use it effectively. This can hinder their ability to take advantage of the many opportunities that technology offers, such as online learning, remote work, and access to information.The consequences of the digital divide are far-reaching. People who are on the wrong side of the divide are at a disadvantage in terms of education and employment opportunities. They may also have limited access to important services such as healthcare and government assistance. In addition, the digital divide can perpetuate existing inequalities in society, making it harder for marginalized groups to break the cycle of poverty.There are several steps that can be taken to bridge the digital divide. One key solution is to increase access to digital technologies, particularly in underserved communities. This can be done through initiatives such as providing subsidies forlow-income families to purchase computers and internet access, as well as building infrastructure to expand high-speed internet to rural areas.Another important step is to improve digital literacy among all populations. Schools and community centers can offer training programs to help people develop the skills they need to navigate the digital world. This can empower individuals to take advantage of the many opportunities that technology offers, such as online learning and remote work.Overall, addressing the digital divide is crucial for ensuring that everyone has equal opportunities to succeed in today's increasingly digital world. By increasing access to technology and improving digital literacy, we can help bridge the gap between those who have access to digital technologies and those who do not. This will not only benefit individuals but also society as a whole by reducing inequality and promoting economic growth.篇3The digital divide refers to the gap between those who have access to modern technology, such as computers and the internet, and those who do not. This divide exists on a global scale and can have profound effects on individuals, communities, and societies as a whole.One of the main factors contributing to the digital divide is economic inequality. In many parts of the world, access to technology is limited by financial constraints. Those who are wealthy can afford the latest gadgets and high-speed internet connections, while those who are struggling to make ends meet may not even have a basic cell phone.Another factor that contributes to the digital divide is geographic location. In many rural areas, access to technology is limited by a lack of infrastructure. Remote communities may not have access to reliable internet connections or even electricity, making it difficult for residents to take advantage of the benefits that technology can offer.Educational opportunities are also impacted by the digital divide. Students who do not have access to technology may fall behind their peers who have access to online resources and tools. This can perpetuate a cycle of poverty and disadvantage, as those who do not receive a quality education are less likely to succeed in the future.The digital divide also has implications for healthcare. Telemedicine, which involves providing medical care remotely through technology, can be a lifeline for those in remote or underserved areas. However, if individuals do not have access to technology, they may not be able to benefit from these services.Efforts are being made to bridge the digital divide and ensure that everyone has access to technology. Governments and non-profit organizations are working to expand internet access to underserved areas and provide training and resources to those who may not be familiar with technology. Companiesare also developing affordable devices and services to make technology more accessible to everyone.In conclusion, the digital divide is a significant issue that has far-reaching effects on individuals and societies. Bridging this gap is essential to ensure that everyone has access to the opportunities and benefits that technology can provide. By working together to address the factors that contribute to the digital divide, we can create a more inclusive and equitable world for all.。
虚拟现实在数字展馆表面重建中的实践应用
法由上至下按顺序地生成全部四叉树节点，高质量实现LOD技术，完成数字展馆场景表面模型
渲染。测试结果显示，该方法重建的数字展馆场景表面三角格网较为均匀、占用内存量小，表面
渲染流畅度高，呈现高质量的数字展馆场景建模效果。
关键词:虚拟现实;数字展馆; Delaunay算法;四叉树算法;渲染;表面重建
中图分类号: TP39 1. 9
平坦水平共同确定，距离越近，平坦水平越差的节
点所在位置对应的渲染精度要求更高，应深度细
分对应的四叉树节点。
其次，基于改进循环结构四叉树算法进行场
景渲染。改进循环四叉树算法的操作原理如图 3
所示。算法实施前确定好模型渲染的需求、四叉
树的层数、四叉树节点数量。循环四叉树结构采 用"上→下"顺序生成四叉树节点 [9 ]。第一步，打造
数字场景渲染速度有效提升。
• 117 •
第1期
黑龙江工业学院学报(综合版)
2024 年
1. 2 . 2 双层渲染裁剪策略
图 3 改进循环结构 四 叉树 函 数实 施流程
U 趋近于1 时说明 三角 格 网 的质量更佳 ， 均匀 程度
第一层"淡人淡出"裁剪。淡人淡出裁剪策略 较好。
注重层次细节，传统层次细节算法切换各个LOD
同时展示了每插入一个点需要搜索的三角形
等级时导致顶点高度值突变，"突越"问题严重，改 数量，用P表示，需要搜索的三角形数量越少说明
进后"淡人淡出"层次细节算法重点缓慢地处理顶 该方法的三角格网构建越高;另外，采用三角格网
点高度值[叫，以高度补偿的模式避免"突越"问 简化率 h表示其精简水平。本文方法的表面三角
数字化时代英语作文高三吉林题
数字化时代英语作文高三吉林题In the digital age, the importance of English has become increasingly evident. As a high school student in Jilin, I have experienced firsthand the challenges and opportunities that come with navigating this rapidly evolving landscape.The digital revolution has transformed the way we communicate, learn, and interact with the world around us. In this new era, English has emerged as a universal language, serving as a vital tool for accessing information, collaborating with individuals from diverse backgrounds, and pursuing educational and professional opportunities.As a high school student in Jilin, I have witnessed the profound impact of digitalization on the education system. The integration of technology in the classroom has revolutionized the learning process, providing students with a wealth of digital resources and innovative teaching methods. Online platforms, virtual classrooms, and interactive learning tools have become integral components of the educational landscape, enabling students to access a global pool of knowledge and engage in collaborative learning experiences.Moreover, the digital age has ushered in a new era of globalization, where borders have become increasingly porous, and the world has become more interconnected than ever before. In this context, proficiency in English has become a crucial asset, allowing individuals to navigate the global marketplace, participate in international exchange programs, and pursue higher education opportunities abroad.As a high school student, I have recognized the importance of honing my English language skills to thrive in this digital age. Through rigorous language classes, immersive language learning experiences, and exposure to English-language media and literature, I have developed a deep appreciation for the richness and nuance of the English language.Furthermore, the digital age has presented new avenues for language learning and practice. Online resources, such as language-learning applications, virtual language exchange platforms, and interactive language-learning communities, have revolutionized the way students can engage with the English language. These tools have enabled me to practice my language skills, connect with native speakers, and immerse myself in authentic cultural experiences, all from the comfort of my own home.In addition to the academic and professional benefits of Englishproficiency, the digital age has also presented new opportunities for cultural exchange and personal growth. Through online platforms and social media, I have been able to connect with individuals from around the world, sharing ideas, perspectives, and experiences. These cross-cultural interactions have not only enriched my understanding of diverse cultures but have also helped me develop empathy, critical thinking, and problem-solving skills – all of which are essential in the digital age.As I look towards the future, I am confident that my proficiency in English will continue to be a valuable asset. In an increasingly globalized and interconnected world, the ability to communicate effectively in English will open doors to a wide range of educational and professional opportunities. Whether it's pursuing higher education abroad, securing a coveted job in a multinational corporation, or engaging in international collaborations, my command of the English language will be a crucial differentiator.In conclusion, the digital age has brought about a profound shift in the way we live, learn, and communicate. As a high school student in Jilin, I have recognized the immense value of English proficiency in navigating this new landscape. Through my dedication to language learning, my embrace of digital resources, and my commitment to cross-cultural exchange, I am confident that I will be well-equippedto thrive in the digital age and make meaningful contributions to the global community.。
一种高效的壁面距离计算方法
一种高效的壁面距离计算方法李广宁;李凤蔚;周志宏【摘要】采用CFD(Computational Fluid Dynamic) 技术进行湍流效应数值模拟时,经常需要计算流场网格点到最近壁面的距离.当网格规模很大,特别是针对一些动网格问题,壁面距离的计算量很大且费时,影响整个流场求解效率.本文对壁面距离计算的直接算法和基于二叉树技术的ADT (Alternating Digital Tree) 快速算法进行了对比分析和研究,提出了一种高效的、基于方盒切割技术的快速计算方法,并采用不同外形的CFD计算网格对该方法进行了验证.计算结果表明,新方法的壁面距离计算效率明显高于直接算法和ADT算法,并具有较好的鲁棒性和通用性,可以便捷地移植到现有的CFD计算程序中,从而提高整个流场的数值计算效率.【期刊名称】《航空工程进展》【年(卷),期】2010(001)002【总页数】6页(P137-142)【关键词】CFD;湍流模型;壁面距离;ADT树;二叉树;方盒切割【作者】李广宁;李凤蔚;周志宏【作者单位】西北工业大学,航空学院,西安,710072;西北工业大学,航空学院,西安,710072;西北工业大学,航空学院,西安,710072【正文语种】中文【中图分类】V211.30 引言采用CFD技术进行数值模拟的物理问题中，常常需要计算空间区域中各离散点到最近壁面的距离，例如，在流场湍流效应数值模拟过程中，许多湍流模型都要计算壁面距离[1-3]。
当几何外形很复杂、网格规模很大时，壁面距离的计算量很大，会对整个流场计算效率产生很大的影响。
尤其是对一些动网格问题，如武器投放、伞兵空降等，需要反复计算壁面距离。
对于某些大型三维静止网格算例，即使是采用Cray C90级别的巨型计算机也需要3个小时完成壁面距离的计算[4]。
因此，本文设计了一种高效、快速的壁面距离计算方法，以提高流场数值模拟的计算效率，满足工程实践的需要。
目前常见的壁面距离计算方法主要分两类：一是基于搜索比较的直接计算方法；二是基于偏微分方程求解的计算方法[5-8]。
叶轮机械全环非定常大规模并行模拟程序设计
叶轮机械全环非定常大规模并行模拟程序设计张健; 唐静; 邱名; 邓有奇; 龚小权【期刊名称】《《空气动力学学报》》【年(卷),期】2019(037)004【总页数】9页(P546-554)【关键词】叶轮机械; 非定常流动; 数值模拟; 全环模拟; 滑移面; 并行效率【作者】张健; 唐静; 邱名; 邓有奇; 龚小权【作者单位】中国空气动力研究与发展中心计算空气动力研究所绵阳 621000【正文语种】中文【中图分类】V211.30 引言叶轮机械内部流动非常复杂,其本质为三维黏性非定常流动。
计算流体力学(Computational Fluid Dynamics,CFD)技术飞速发展,其具备计算耗时短,成本相对较低,并且可以多维度地模拟出叶轮机内部复杂的非定常流动细节的优点,因而越来越多地用于叶轮机械的气动设计和分析当中。
叶轮机内部非定常流动的来源有多种,动静叶片排的相对转动、激波边界层干扰、尾迹传播、二次流等都是造成流动不稳定的原因。
通过数值模拟对上述非定常现象进行研究的关键在于如何建立模拟转静叶片相对运动过程的模型。
目前工业上一般采用混合平面(Mixing Plane)模型[1],该模型将转/静界面上下游相同展向高度处的通量通过周向平均后进行交换,将非定常计算简化为对一个叶片流道的定常计算,虽然大大减小了计算量,然而却无法捕捉到转静子之间相互干扰等非定常现象。
采用叶片约化技术[2],将叶片在周向方向上按照一定比例进行几何缩放,能够使转静叶片数具有较大公约数进而约化为少量几个叶片通道进行非定常计算,但是由于改变了实际的几何尺寸,这种方法会存在较大误差。
He和Ning提出的非线性谐波法(Non-linear Harmonic Method,NLH)[3]可以看作是一种定常/非定常混合方法,其基本假设是流场的主要扰动是由于叶片通过频率(Blade Passing Frequence,BPF)引起的,从而将流场变量分解成为时间平均值和多个不同频率谐波的扰动组成,BPF的整数倍数分别代表了不同谐波。
笛卡尔网格生成中的相交算法
笛卡尔网格生成中的相交算法
张立;何冰;封卫兵;张武
【期刊名称】《计算机辅助工程》
【年(卷),期】2013(022)001
【摘要】研究三维空间笛卡尔网格与三角形面网格的相交判断算法—-
ADT(Alternating Digital Tree)算法和KD (K-Dimensional)树算法,分别用球体模型和飞机模型对ADT与KD树进行分析,比较二者快速相交判断时的查找效率.结果表明:同一种模型下ADT比KD树平衡,树的深度小；ADT的查找效率明显比KD 树高；影响KD树查找时间的主要因素是查找次数.整体来看,在快速相交判断中采用ADT性能更高.
【总页数】7页(P71-76,78)
【作者】张立;何冰;封卫兵;张武
【作者单位】上海大学计算机工程与科学学院,上海200072;上海大学计算机工程与科学学院,上海200072;上海大学计算机工程与科学学院,上海200072;上海大学计算机工程与科学学院,上海200072
【正文语种】中文
【中图分类】O241.82;O35
【相关文献】
1.各向异性自适应笛卡尔网格生成方法研究 [J], 逯雪铃;叶正寅
2.笛卡尔网格生成过程中的内外判断问题 [J], 逯雪铃;叶正寅
3.基于STL文件的笛卡尔网格生成方法研究 [J], 肖涵山;刘刚;陈作斌;程克明
4.特征约束网格生成算法在GIS中的实现 [J], 宋明明;吴陈
5.四边形网格生成中的前沿边生长改进算法 [J], 陈阳;崔汉国;刘健鑫;代星
因版权原因，仅展示原文概要，查看原文内容请购买。
天津市第一中学2025届高三英语下学期第四次月考试题含解析
天津市第一中学2025届高三英语下学期第四次月考试题（含解析）第一节（共 5 小题；每小题 1 分，满分 5 分）听下面五段对话。
每段对话后有一个小题，从题中所给的 A、B、C 三个选项中选出最佳选项，并标在试卷的相应位置。
听完每段对话后，你将有 10 秒钟的时间来回答有关小题和阅读下一小题。
每段对话仅读一遍。
1. Which color does the man prefer?A. Blue.B. Red.C. White.2. Where does this conversation probably take place?A. At a repair shop.B. At a gas station.C. In a parking lot.3. What do we know from this conversation?A. The wind has stopped.B. The rain has stopped.C. It is still raining.4. What does the woman tell us about Paul?A. He spends too much money.B. He likes expensive watches.C. He really does like television.5. What is the most probable relationship between the speakers?A. Schoolmates.B. Colleagues.C. Partners.其次节（共 10 小题；每小题 1.5 分，满分 15 分）听下面几段材料。
每段材料后有几个小题，从题中所给的 A、B、C 三个选项中选出最佳选项，并标在试卷的相应位置。
听每段材料前，你将有时间阅读各个小题，每小题 5秒钟；听完后，各小题将给出 5 秒钟的作答时间。
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31, 1-17 (1991)
AN ALTERNATING DIGITAL TREE (ADT) ALGORITHM FOR 3D GEOMETRIC SEARCHING AND INTERSECTION PROBLEMS
0029-598 1/9 1/010o0 1-1 7$08.50 0 1991 by John Wiley & Sons, Ltd.
Received 25 October 1989 Revised 9 April 1990
2
J. BONET AND J. PERAIRE
treatment of any geometrical object in an N dimensional space as a point in a 2N dimensional space will be introduced, thereby allowing the proposed technique to be employed for the solution of geometric intersection problems. Emphasis has been made on the FORTRAN 77 implementation, not because we consider it to be the most suitable language for this type of application, but because most scientific programming is still done using this language. The implementation is simpler in languages like Pascal or C which feature recursion and dynamic allocation. The particular application which has motivated the development of this work is the automatic generation of tetrahedral finite element meshes by the advancing front t e ~ h n i q u e . ~ The -~ application of the proposed algorithm to this problem will be discussed in the last section of this paper. BINARY TREE STRUCTURES Binary trees are one of the most important non-sequential types of data structures. They provide the basis for several searching algorithms, including the one to be presented here. It is therefore necessary to introduce some basic concepts and terminology related to binary tree structures. More detailed expositions can be found in References 5 and 10. Dejnition and terminology Originally, tree structures were conceived as a systematic way of storing a collection of data items which would enable not only a quick access to the information stored, but also frequent insertions of new items as well as deletion of unwanted items. This degree of flexibility requires the storage of data items in non-sequential locations of the computer memory. As Figure l(a) illustrates, to achieve this, each data item is extended by the addition of two integer values, known as the left and right links,and stored in what is known as a node of the tree. Each added link can either be equal to zero or equal to the position in memory where another node of the tree can be found. Hence, from one node of the tree it is possible to reach at most two other nodes. Moreover, in order to ensure that every node can be reached, these links must be such that for each node except one, known as the root, there is one and only one link pointing at it. This definition establishes a hierarchy of nodes: the root at the top level of the hierarchy points at 0 , l or 2 nodes at the next level; each of these in turn points at other 0 , l or 2 nodes at the next level of the hierarchy; and so forth. This hierarchical structure inspires the graphical representation shown in Figure l(b) for a simple tree comprising only eight nodes {A, B, C, D, E, F, G, H}. Genealogical terms are normally used to describe the relative position of nodes in a tree: when a node points at a second node, the former is called thefather of the latter, and this the son of the former node. A node without sons, that is, with both links blank, is called a terminal node, and the only node without a father is the root (node A in Figure l(b)). Given a node, the set of nodes formed by itself together with all its descendants constitutes a subtree of the main tree. For instance, in Figure l(b) the trees {C, D, E, F, G, H} and {E, G, H) are subtrees of the main tree rooted at C and E respectively. Tree traversal To retrieve information stored in a given node requires knowledge of its location in memory, which is kept by its father. Hence, a node in the tree can only be examined or visited if all its ancestors are visited first. However, it is possible to systematically examine each node in such a
SUMMARY A searching algorithm is presented for determining which members of a set of n points in an N dimensional space lie inside a prescribed space subregion.The algorithm is then extended to handle finite size objects as well as points. In this form it is capable of solving problems such as that of finding the objects from a given set which intersect with a prescribed object. The suitability of the algorithm is demonstrated for the problem of three dimensional unstructured mesh generation using the advancing front method.