Task Package 1 News on Solar Power

设计宇宙飞船的英语作文Designing a Spaceship for the Future of Human Exploration.Humanity's quest to explore the vastness of space has always been a fascinating and challenging endeavor. As we continue to push the boundaries of our knowledge and understanding, the need for advanced and innovative spacecraft becomes increasingly apparent. Designing a spaceship for the future of human exploration requires careful consideration of various factors, including propulsion systems, life support systems, structural integrity, and more.Propulsion systems are crucial to the success of any spacecraft. The most efficient and sustainable propulsion systems are those that utilize renewable energy sources, such as solar power. Solar panels can be installed on the exterior of the spacecraft to harness the sun's energy and convert it into power for the ship's engines. This not onlyreduces the reliance on finite fuel resources but also ensures a constant supply of power for extended missions.Life support systems are equally important, as they provide the necessary environment for the crew to survive and thrive during their journey. These systems must be able to provide oxygen, water, food, and waste disposal, among other essential services. Advanced recycling systems can be incorporated to reduce the amount of consumables needed and minimize waste production. Additionally, the spacecraft should be equipped with advanced medical facilities to handle any medical emergencies that may arise during the mission.Structural integrity is another critical aspect of spacecraft design. The spacecraft must be able to withstand the extreme conditions of space, including radiation, temperature extremes, and micrometeorite impacts. Lightweight materials, such as carbon fiber and titanium, can be used to construct the hull of the spacecraft, providing both strength and durability while minimizing weight. Furthermore, the spacecraft should be designed withredundancies and backup systems to ensure mission success even in the event of component failure.In addition to these basic requirements, the spacecraft should also be equipped with advanced navigation and communication systems. Navigation systems are crucial for accurate navigation and maneuvering in space, while communication systems are essential for maintaining contact with Earth and relaying mission updates and data. These systems must be highly reliable and secure to ensure smooth communication and data transmission.Furthermore, the design of the spacecraft should take into account the psychological and physiological needs of the crew. Extended periods of isolation and confinement can have significant effects on the crew's mental and physical health. Therefore, the spacecraft should be designed to promote crew well-being, with amenities such as exercise equipment, entertainment systems, and even spaces for relaxation and meditation.Finally, the design of the spacecraft must alsoconsider the mission objectives and the environment it will be exploring. Whether the mission involves orbiting a planet, landing on a surface, or exploring a deep-space object, the spacecraft must be capable of adapting to the unique challenges of each environment. This may require the integration of specialized equipment and technologies to support the specific scientific or exploration goals of the mission.In conclusion, designing a spaceship for the future of human exploration is a complex and multifaceted task. It requires a deep understanding of the challenges and opportunities presented by space travel, as well as a commitment to innovation and continuous improvement. By combining advanced technology, sustainable design, and a focus on crew well-being, we can create spacecrafts that will enable humanity to explore the vast reaches of space and expand our knowledge and understanding of the universe.。

2022考研英语阅读印度太阳能Solar power in India印度太阳能Waiting for the sun等待着艳阳Is the sun the answer to India s energy problems?太阳能是印度能源问题的解决方法吗?ON A salt plain near the border with Pakistan lies half a billion dollars worth of solar-energykit paid for by firms from all over the world.靠近巴基斯坦边界的一块盐地，安装了来自全球的公司价值五亿美元的太阳能设备。

A million panels stretch as far as the eye can see.目所能及的就有一百万块太阳能板了。

Past a dishevelled brass band is atent crammed with 5,000 people who cheer when Narendra Modi, the chief minister ofGujarat, declares the solar park open:穿过一群散乱的铜管乐队就是一个挤满了正在庆祝的5000人帐篷区，此时，古吉拉特邦的首席部长纳伦德拉莫迪宣布太阳能电厂正式运行，I pray, sun god, that today Gujarat will show the way to the rest of the world for solarenergy.我盼望太阳神庇护我们，今日古吉拉特邦将向世界其他地方展现通向太阳能的道路。

Despite the uncomfortable cult of personality around Mr Modi, Gujarat is an easy place todo business.除了对莫迪的个人崇拜令人感到不愉快轻松外，古吉拉特邦还是一个简单经商的地方。

托福听力TPO12真题分类之环境科学托福听力考试贯穿于整个考试中，很多题目都涉及听力，所以建议同学们要重视托福词汇的记忆，下面是小编给同学们带来的托福听力TPO12分类之环境科学，跟着小编的脚步一起来认真分析一下吧!托福听力TPO12分类之环境科学Lecture 4 (environmental science)NarratorListen to part of a lecture in an environmental science class.ProfessorAll right folks, let's continue our discussion of alternative energy sources and move on to what's probably the most well-known alternative energy source - solar energy. The sun basically provides earth with a virtually unlimited source of energy every day, but the problem has always been how do we tap this source of energy.Can anyone think of why it's so difficult to make use of solar energy?Female studentBecause it’s hard to…um… gather it?ProfessorThat's exACTly it. Solar energy is everywhere, but it's also quite diffused. And the thing is the dream of solar energy is not a new one. Humanity has been trying to use the sun's light as a reliable source of energy for centuries. And around the beginning of the 20th century there were ACTually some primitive solar water heaters on the consumer market. But they didn't sell very well. Any of you wanna guess why?Female studentWell, there were other energy choices like oil and natural gas,right?ProfessorYeah, and for better or for worse, we chose to go down that path as a society. When you consider economic fACT ors, it's easy to see why. But then in the 1970s, there was an interest in solar energy again. Why do you think that happened?Male studentBecause oil and natural gas were...er...became scarce?ProfessorWell, not exACTly. The amount of oil and natural gas in the earth was still plentiful, but there were other reasons. It's a political thing really and I'm gonna get into that now. So what happened in the 1970s was oil and natural gas became very expensive very quickly, and that spurred people to start looking into alternative forms of energy, solar energy probably being the most popular. But then in the 80s, this trend reversed itself when the price of oil and natural gas went down. All right. Let's shift our focus now to some of the technologies that have been invented to overcome the problem of gathering diffused solar energy. The most basic solution is simply to carefully place windows in a building, so that the sun shines into the building and then it's absorbed and converted into heat. Can anyone think of where this is most commonly used?Female studentGreenhouses.ProfessorYep, greenhouses, where plants are kept warm and provided with sunlight because the walls of the building are made entirely of glass. But we do also have more complex systems that are used for space heating and they fall into two categories: passive andACTive heating systems. Passive systems take advantage of the location or design of a house. For example, solar energy is gathered through large glass panels facing the sun.The heat is then stored in water-filled tanks or concrete. No mechanical devices are used in passive heating systems. They operate with little or no mechanical assistance. With ACTive systems, on the other hand, you collect the solar energy at one location, and then you use pumps and fans to move heat from the collectors through a plumbing system to a tank, where it can be used to heat a home or to just provide hot water.Male studentExcuse me professor, but I've got to ask. How can solar energy work at night or on cloudy days?ProfessorThat's...well...that is a really good question. As a matter of fACT, science is still working on it, trying to find ways of enhancing energy storage techniques so that the coming of night or cloudy days really wouldn't matter.That is the biggest drawback to solar energy - the problem of what do you do in cases where the sun's light is weak or virtually non-present. So the storage of solar energy, lots of solar energy, is a really important aspect.Female studentDoes that mean that solar energy can only be used on a small scale, like heating a home?ProfessorWell ACTually, there have been some attempts to build solar energy power plants. The world's largest solar power plant is located in Kramer Junction California. It can generate 194 megawatts of electric power, but that's just a drop in the bucket.Right now the utility companies are interested in increasing the capacity of the Kramer Junction Plant, but only time will tell if it will ever develop into a major source of power for that region, considering the economic and political fACTors involved.托福听力对话常见词：学术研究1. hypothesis 假说2. hypothesize v.假设3. alternative hypothesis 另一种假说4. null hypothesis 无效假说, 零假说5. collect data 收集信息6. process data 处理信息7. survey 调查8. questionnaire 问卷9. experiment 实验10. interfere(实验)干预11. observation 观察12. analyze data 分析数据13. interpret data 解释数据14. analytical 分析的15. experiment subject 实验对象16. sample 样品17. control group 控制组(被实验的)18. reference group 参照组(未经实验的)19. field research 实地研究托福听力对话常见词：校园工作1. letter of reference/recommendation 推荐信2. competitive 有竞争力的3. benefit future career 对未来职业有帮助4. qualification资格/qualified 合格的5. Resume, CV 简历6. financial aid 经济援助7. scholarship 奖学金8. fellowship 学术奖金9. teaching assistantship 助教奖学金10. research assistantship 研究奖学金11. grant 助学金12. loan 贷款13. need-based以需求为基础14. merit-based 以优秀为基础15. student union/government 学生会16. Society / association / club 协会17. membership 成员资格18. career service center 就业指导中心托福听力对话常见词：住宿篇1. campus housing 校内住宿2. on/off campus 校内/外3. accommodation n.住处, 膳宿4. residential area 住宿区5. apartment 公寓6. dormitory(dorm)宿舍7. lounge n.(公共)休闲区8. roommate 室友9. corridor n. 走廊,过道10. lease n.租借, 租约11. landlord 房东/ landlady女房东12. rent 租金13. tenant 房客14. balcony 阳台15. single room 单人房16. double room 双人房17. housing maintenance 宿舍维修18. water pipe 水管19. heating system 暖气20. electric heater 电加热器21. air conditioning 空调22. leakage 漏水23. custodian 宿舍管理员24. janitor 看门人，清洁人员托福听力TPO12分类之环境科学。

What’s in the PackageInstallation and Operation GuideVersion v. 1.2SolarEdge Energy Bankfor use with SolarEdge inverters© SolarEdge Technologies, Ltd.All rights reserved.Version:1.2,September 2021Subject to change without notice.SolarEdge Energy BankMounting bracketDecorative cover Required Personnel and ToolsWARNING!Before installing or operating the SolarEdge Energy Bank (referred to as the “Battery”), read the Safety and Handling instructions at the back of this page.x 2Cover screwsDolly with liftand ratchet strapsDrillMounting screws -max M10min 2Min 2 qualified installersMC4crimperLevelHandles (available from SolarEdge)x 4DC cable600V insulatedBranch connectors (optional, available from SolarEdge)x 2Torque wrench Phillips screwdriver x 2Mountingbracket screws MC4connectors Support Contact InformationIn case of any technical issues with SolarEdge products,please contact us at:https:///service/support Conduit holderSolarEdge Energy Netplug-in (available from SolarEdge)423Hang battery on mounting bracket1.Lift the battery to the height of the mounting bracket.2.Hang the battery on the mounting bracket, while holding it by the handles.3.Secure with a mounting bracket screw (supplied) on each side.Apply a torque of 42in-lbs/4.7N*m.1245Prepare cables1.Mount the conduit holder.2.Pass the DC cables and grounding cable through the conduit holder at the bottom of the battery.3.Connect the grounding cable to the grounding terminal with a torque of 66in*lbs/7.5 N*m.4.Crimp the DC cables to the MC4 connectors (supplied) and tighten the MC4 connector glands with a torque of 30 in*lbs/3.4N*m.31Connect to inverter1.Make sure the inverter is OFF.2.Connect the DC cables to the DC+ and DC-inputs. Observe correct polarity.3.Install the SolarEdgeEnergy Net plug-in and antenna in the inverter.See the installation guide:4.Connect cables to the inverter.See the Connection and Configurationapplication note.-+263Energy NetOFF41WARNING!This symbol on the product or in the accompanying documentation denotes a hazard. It calls attention to a procedure that,if not correctly performed or adhered to,could result in injury or loss of life.Do not proceed beyond a warning note until the indicated conditions are fully understood and met.Install mounting bracket 1.Level the bracket.2.Mark two drilling spots.Use either the inner or outer pair of holes.If necessary,you can use the additional holes to secure the bracket.3.Drill holes in the installation surface.4.Install the mounting bracket and secure with screws.When selecting the installation location:•Maintain a clearance of min 8 in/20 cm from other objects.•Make sure the max distance from the inverter is max164 ft/50 m.Make sure the installation surface sustains the weight of the battery (267lbs/121kg).16”/ 40.5 cm24”/ 61 cm 23421min 8 in/20 cmmax 164 ft/50 mFor the SolarEdge Energy Bank –Emergency Response guide,including emergency phone numbers, scan the QR code:FireextinguisherTransport battery1.Screw in all FOUR handles to the battery frame.2.Place the battery upright on a dolly and secure it with straps.Caution!Stand the battery on the rubber protector only!3.Transport the battery to the installation location.;1233CAUTION!Make sure to screw in the handles all the way.Do not use a bent, cracked, or otherwise damaged handle.Install fire extinguisherLong-nose pliers123314e long-nose pliers to straighten and remove thesafety pin.2.Remove the sticker that covers the fire extinguisher’s service hole.3.Carefully insert the fire extinguisher into the service hole.4.Secure the fire extinguisher with seven Allen screws (supplied). Apply a torque of 40in-lbs/4.5N*m.SAFETY AND HANDLING INSTRUCTIONSRead this entire document before installing or operating the SolarEdge Energy Bank battery (referred to as the “Battery”). Failure to do so or to follow any of the instructions or warnings in this document can result in electrical shock, serious injury,or death, or may damage the Battery and other property.Do not discard this document!After installation,keep it adjacent to the Battery for future reference!Installation•Install the battery according to national and local codes and standards and in locations compliant with local building codes and standards.•The Battery installation must be carried out only by qualified electricians who have been trained in handling low voltage electricity works.•The Battery is heavy. Adhere to local regulations for material handling and heavy lifting, when installing heavy equipment.•Do not install the Battery in habitable spaces, including sleeping rooms.•Make sure the mounting surface can sustain the total weight of the Battery and mounting bracket. •Do not install the Battery, if it has been dropped, crushed, or has signs of physical damage.•When the Battery is installed in a residential environment, fire detection and protection equipment must be installed in accordance with local building and fire codes.•Do not install the Battery near heating equipment, ignition sources, or open flames.•Install the Battery only on non-combustible surfaces and under non-combustible ceilings, overhangs, or eaves.•Do not install the Battery in proximity to gas meters, valves, regulators, lines, or gas appliances. Follow local codes. However,2m /6ft or more spacing is highly recommended.A failing battery may ignite flammable gasses resulting in property damage, serious injury,or death.•Avoid installing the Battery in direct sunlight.•Install the Battery in a location protected from flooding.•Do not install the Battery in the vicinity of water sources, including downspouts, sprinklers, or faucets.•When installing the Battery in a garage or near vehicles, keep it out of the driving path. If possible, install the Battery on a side wall and/or above the height of vehicle bumpers.•Before beginning the wiring, ensure that the Battery is switched off. Also, make sure that the DC safety switch of all inverters in the PV system is turned off.Operation•The Battery contains rechargeable lithium-ion cells that are potentially hazardous and can present a serious fire hazard, injury and/or property damage if damaged, defective or improperly used.•Lithium-ion batteries and products that contain lithium-ion can expose you to chemicals, including antimony trioxide,cobalt lithium nickel oxide, and nickel, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information,go to .•In case of an electrolyte leak from the Battery, avoid contact with electrolyte and follow the instructions in the SolarEdgeEnergy Bank –Emergency Response Guide.•Use the Battery only as directed in this document.•Do not use the Battery if it is defective, appears cracked, broken, or otherwise damaged, or fails to operate.•The Battery and its components are not user-serviceable.•Do not attempt to open, disassemble, repair, tamper with, or modify the Battery. The Battery cells are not replaceable.•Do not operate the Battery at ambient temperatures of above 50°C/122°F or below -10°C/14°F.•Do not expose the Battery or its components to direct flame.•Do not store flammable liquids or gasses in the same room with the Battery. When the Battery is installed outdoors, keep any flammable liquids or gasses at a distance of at least 15m /50ft from the Battery.•Do not place any combustible items within less than 2.5 m / 8 ft of the Battery.•If the Battery catches fire, or if fire breaks out near the Battery, call the fire department immediately and follow the instructions in the SolarEdge Energy Bank –Emergency Response Guide.•The Battery is prone to re-ignition after extinguishing. Use caution and follow the emergency response instructions.•Do not immerse the Battery or its components in water or other fluids.•Charge and discharge voltage: 350-450 Vdc.•Operating the Battery in temperatures outside the specified range might cause damage to the Battery.•Do not use solvents to clean the Battery, or expose the Battery to flammable or harsh chemicals or vapors.•Do not use fluids, parts, or accessories other than those specified in this guide, including use of non-genuine SolarEdge parts or accessories, or parts or accessories not purchased directly from SolarEdge or a SolarEdge certified party.•After the installation, do not place the Battery in storage conditions for more than one (1) month, or permit the power feed to the Battery to be discontinued for more than one (1)month.•Do not paint any part of the Battery, including any internal or external components such as the exterior shell or casing.•Ensure that snow does not accumulate around the Battery.• A non-functioning Battery must be handled with caution. The Battery state of charge and risk of venting may be unknown.Contact SolarEdge for assistance.•Do not attempt to remove or transport a damaged or non-functioning battery. Contact SolarEdge or your SolarEdge certified installer for support.•This symbol on the product means: Do not dispose of this product with general household waste. Consult your local regulations for proper disposal instructions.Mount decorative cover1.Remove the rubber protector.2.Mount the decorative cover. Make sure the cover clips to the battery frame, where shown.3.Fasten the cover with two bolts (supplied).12310clipConfigure installation1.Run SetApp.2.Scan the QR code on the inverter.3.Follow the on-screen instructions.For post-installation settings, see Connection and Configuration application note.The battery operation is managed by the SolarEdge inverter connected to the battery.3Device Manager Found new devices Add New Devices…Finish SettingsCommissioning SetApp129`I0PON2 sec12Power on and associate1.To power on and operate the battery, turn on the DC circuit breaker.2.To associate with the inverter, move the battery’s ON/OFF/P switch to P for 2 seconds and then release.8WARNING!To power off the battery in case of emergency:Turn off the ON/OFF/P switch and DC circuit breaker.FCC and Emission ComplianceThe Battery has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules in the United States,and local regulations in other countries.The Battery contains FCC ID: 2AGPT-ENET, IC: 20916-ENET.These limits are designed to provide reasonable protection against harmful interference in a residential installation. The Battery generates,uses and can radiate radio frequency energy and,if not installed and used in accordance with SolarEdge’sinstructions,may cause harmful interference to radio communications.However,there is no guarantee that interference will not occur in a particular installation.If the Battery does cause harmful interference to radio or television reception,which can be determined by turning the Battery off and on, you are encouraged to try to correct the interference by one or more of the following measures:•Reorient or relocate the receiving antenna.•Increase the separation between the Battery and the receiver.•Consult the installer or an experienced radio/TV technician for help.Changes or modifications not expressly approved by SolarEdge for compliance may void the user’s authority to operate the Battery.LED IndicationsPowerCommFaultBlinkingCharge/discharge FlickeringStandby/DC pairingONNetwork comm OK BlinkingSearching for networkON Fault Fast Blinking FW updateAll LEDs ON Boot/Reset`IP7Connect additional batteries (optional)1.Make sure all batteries are properly grounded using the grounding terminal.2.Connect branch connectors to the battery’s DC inputs. 3.Connect DC cables from the inverter and the next battery to the branch connectors.Connect cables between the batteries , as described above.-+DC to inverter/prev. batteryDC to next battery231。

国家开放大学《理工英语1》边学边练参考答案Unit 1　Future HousesListening and Speaking 1再听一听对话，选择合适的单词或短语完成句子。

international student subject semester nice to meet youthink of major Let's goSun Li studies in the Open University of Jiangxi as a part-time student. She meets another student, Henry Wang, on campus.H:Hello, I'm Henry Wang, a new part-time（International student）from America.S:（Nice to meet you）I'm Sun Li.H:Nice to meet you too. Are you a student of this university, too?S:Yeah, this is my second year. I study Architecture. And what's your major?H:Oh, My（major）is Energy and Environment. So, what subjects do you study this term?S:This（semester）we study English, Engineering Drawing, Construction Technology, and Building Materials.H:Oh, I see. I have English classes too. I have Air Pollution Control, Pollution Analysis, and Climate Change Control Technology.S:Oh, really?! What do you（Think of）your major?H:It's wonderful. I think the classes are really interesting, but Pollution Analysis isn't my bes（subject）. I like Climate Change Control Technology better. How about you?S:I like Building Materials best.H:Well, what time is it now?S:It's 14:20. It's time for class. Let's go.H:OK.（Let's go）.Listening and Speaking 2再听一听对话，选择合适的单词或短语完成句子。

1. What are the speakers talking about?A．Gifts for Jason.B．A baseball game.C．The woman's retirement.2. What does the woman suggest the man do?A．Drink some coffee.B．Get up early tomorrow.C．Finish reading tonight.3. When can the woman take a vacation?A．At the end of August.B．At the end of June.C．This week.4. What are the two speakers mainly talking about?A．The weather of Paris.B．A terrible accident.C．A piece of news.5. How was the woman’s trip?A．Terrible.B．Amazing.C．Interesting.二、听力选择题6. 听下面一段较长对话，回答以下小题。

1. What do people think of the movie?A．Complicated.B．Interesting.C．Well-acted.2. Who is the man’s favorite actor?A．Lamb.B．Katherine.C．Jim Rodgers.3. What will the man probably do?A．Watch the movie on TV.B．Buy a video of the movie.C．Search information about the movie online.7. 听下面一段较长对话，回答以下小题。

1. What are the speakers talking about?A．Sea power.B．Wind power.C．Solar power.2. What season is it?A．Summer.B．Autumn.C．Winter.3. How does the woman feel about the things they talked about?A．Optimistic.B．Puzzled.C．Doubtful.8. 听下面一段较长对话，回答以下小题。

雅思全真模考试题及答案听力部分Section 1: 旅游咨询1. What is the name of the travel agency?A. Sunshine TravelB. Moonlight TravelC. Starlight TravelAnswer: A2. What is the departure date for the trip?A. 15th MarchB. 25th MarchC. 5th AprilAnswer: B3. Which destination is included in the package?A. ParisB. RomeC. BarcelonaAnswer: CSection 2: Campus Map4. Where is the library located?A. Next to the cafeteriaB. Opposite the sports centerC. Beside the main entranceAnswer: B5. What is the quickest way to get to the language center?A. By the footpath through the parkB. Through the central courtyardC. Along the main roadAnswer: A6. Where can students find the computer lab?A. In the basement of the science buildingB. On the second floor of the arts buildingC. On the ground floor of the administration building Answer: A阅读部分Passage 1: The History of Chocolate7. What was the primary use of cacao beans in ancient Mesoamerica?A. As a form of currencyB. For religious ceremoniesC. As a medicinal ingredientAnswer: A8. When was chocolate first introduced to Europe?A. In the 16th centuryB. In the 17th centuryC. In the 18th centuryAnswer: A9. What is the main ingredient in modern chocolate bars?A. Cocoa powderB. Cocoa butterC. Cocoa liquorAnswer: CPassage 2: Renewable Energy Sources10. Which renewable energy source is the most cost-effective?A. Solar powerB. Wind powerC. HydropowerAnswer: B11. What is the main advantage of using biofuels?A. They are renewableB. They produce less pollutionC. They are widely availableAnswer: A12. What is the primary drawback of tidal energy?A. It requires large infrastructureB. It is not reliableC. It is expensive to maintainAnswer: A写作部分Task 1: Bar Chart13. Describe the bar chart below, which shows the number of visitors to five different museums in a city over a year.[Bar Chart: Museum Visitors]Task 2: Opinion Essay14. Some people believe that the government should provide financial support to creative artists such as painters and musicians. To what extent do you agree or disagree with this statement? Give reasons for your answer and include any relevant examples from your knowledge or experience.口语部分Part 1: Hometown15. Where are you from?16. What is the most famous tourist attraction in your hometown?17. How has your hometown changed over the past few years?18. What do you like most about your hometown?Part 2: Describe a historical event you are interested in.19. What is the event?20. When and where did it happen?21. Why are you interested in this event?22. How did you learn about this event?Part 3: Discuss the importance of history.23. Why do some people think history is important?24. Do you think history has any relevance to modern life?25. How can history be taught in schools to make it more interesting?26. What are the benefits of learning about history?结束语：以上为雅思全真模考试题及答案，希望对您的雅思备考有所帮助。

人教版高中英语完型填空练习题50题【含答案解析】1. I always enjoy the ________ atmosphere in the library.A.quietB.noisyC.crowdedD.empty答案解析：A。

图书馆通常是安静的地方，quiet 符合图书馆的氛围。

noisy 吵闹的不符合图书馆的环境；crowded 拥挤的，图书馆不一定总是拥挤的；empty 空的，也不符合图书馆一般的状态。

2. The teacher gave us a difficult ________ to solve.A.problemB.questionC.taskD.challenge答案解析：A。

problem 通常指比较难解决的问题；question 一般指需要回答的问题；task 任务；challenge 挑战。

这里说解决，通常用problem 更合适。

3. We had a ________ discussion in class today.A.livelyB.boringC.quietD.silent答案解析：A。

discussion 讨论，lively 生动活泼的讨论符合课堂情况。

boring无聊的不符合一般课堂讨论的期待；quiet 和silent 都太安静，不太符合讨论的场景。

4. The school ________ is very beautiful.A.buildingB.gardenC.playgroundD.library答案解析：A。

学校的建筑通常是比较有代表性的，garden 花园、playground 操场、library 图书馆都只是学校的一部分，building 建筑更全面。

5. I have a lot of ________ to do after school.A.homeworksB.workC.houseworkD.tasks答案解析：D。