1、高考资源网() 您身边的高考专家20192020学年第二学期期中试卷高二英语2020.05注意事项:1.本试卷分为第I卷(选择题)和第II卷(非选择题),满分150分。考试时间120分钟。2.请将第I卷的答案填涂在答题卷上,第II卷请直接在答题卷上规定的地方作答。答题前,务必将自己的学校、姓名、考试号等相关信息写在答题卷上规定的地方。第I卷(选择题,共75分)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卡上。第一节(共5小题;每小题1分,满分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
2、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 will the woman do today?A. Go on a date. B. Visit a museum. C. Make ice cream.2. Why was the man late?A. He didnt feel well. B. He set off late. C. He got lost.3. What does the woman probably think of working while in college?A. Use
3、ful. B. Difficult. C. Unnecessary.4. What are the speakers talking about?A. A rock. B. A movie. C. A spacecraft.5. When is Simon supposed to arrive?A. 7:30. B. 8:00. C. 8:10第二节(共15小题,每小题1分,满分15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。每段对话或独白读两
4、遍。听第6段材料,回答第6、7题。6. What is the mans twin sister?A. A model. B. A doctor. C. A TV star.7. How old is the man?A. 22. B. 24. C. 20.听第7段材料,回答第8、9题。8. What color was the hall before?A. Silver. B. Grey. C. White.9. Which place will be finished soon?A. The ticket office. B. The snack bar. C. The bookstore
5、.听第8段材料,回答第10至12题。10. What does the man want to do?A. To exchange for some cash. B. To put aside some money. C. To lend some money.11. Which is better in cashing a travelers check according to the woman?A. A stocking center. B. A hotel. C. A bank.12. Which of the following neednt the man offer to th
6、e woman?A. Foreign exchange request. B. Passport number. C. ID card.听第9段材料,回答第13至16题。13. For what was Google fined $5 billion?A. Breaking competition rules.B. Presenting wrong search results.C. Producing poor-quality products.14. What is the size of the fine like according to the woman?A. Very small
7、. B. Rather large. C. Acceptable.15. When did the EU fine Google $ 2.8 billion?A. In 2016. B. In 2017. C. In 2018.16. Where does the conversation most probably take place?A. In a classroom. B. At the office. C. At home.听第10段材料,回答第17至20题。17. What is the passage mainly about?A. The history of the scho
8、ol. B. The courses for the term. C. The plan for the day.18. Where can the visitors learn about the subjects for new students?A. In the school hall. B. In the science lab. C. In the classroom.19. What can students do in the practical areas?A. Take science courses. B. Enjoy excellent meals. C. Attend
9、 workshops.20. When are the visitors expected to ask questions?A. During the lunch hour. B. After the welcome speech. C. Before the tour of the labs.第二部分 阅读理解(共20小题,每小题2分,满分40分)第一节(共15小题;每小题2分,满分30分)阅读下列短文,从每题所给的四个选项(A、B、C、和D)中,选出最佳选项,并在答题卡上将该项涂黑。ADuring the outbreak of novel coronavirus, cities are
10、 locked down and borders are closed. Science, on the contrary, is becoming more open. And this open science is already making a difference.Soon after the epidemic started in China, a research team from Fudan University in Shanghai successfully sequenced(测定序列)the DNA of the virus. But they didnt keep
11、 the information to themselves. Instead, they placed the sequences on GenBank, an open-access data platform, so researchers around the world could download them for free and start studying the virus.Due to this openness, pharmaceutical(制药的)companies across the globe are now able to work simultaneous
12、ly(同时地)to develop a vaccine. There may be room for multiple different vaccines for different purposes and different age groups, Amesh Adalja, a senior scholar at the Johns Hopkins University Center for Health Security in the US, told Al Jazeera. The bigger menu we have of vaccines, the more resilien
13、t(有适应力的)well be against coronavirus outbreaks in the future.Major drug companies around the world are also sharing their study results. Remdesivir, a drug originally developed by US company Gilead Sciences to treat Ebola, is found to be promising in fighting against the novel coronavirus. Currently,
14、 two trials of the drug are already underway in China, and the results might be available as soon as April, according to The Verge.This openness in science is going to be even more critical in the future. With climate change, increasing globalization, and population shifts, epidemics will not go awa
15、y, and might even become more frequent, Dan Barouch, a Harvard Medical School professor, told Harvard Magazine.He said, No one group can do everything. It has to be a coordinated(合作的)approach. But I do think that the world has a greater sense of readiness this time to develop knowledge, drugs, and t
16、herapeutics(疗法)very rapidly.Every epidemic is indeed a crisis, but it can also be a learning opportunity. One redeeming(补偿的)factor of the COVID-19 outbreak is that it is helping science adapt for the better.21. What does the article mainly talk about?A. Coordinated efforts to fight the epidemic.B. S
17、omething positive weve learned from the epidemic.C. The significance of openness and sharing of scientific knowledge.D. What needs to be done to prevent future epidemics.22. What is the positive effect of the research team from Fudan University placing the genetic sequence of the virus onto GenBank?
18、A. They alerted the world to the danger of the virus.B. They helped remove peoples fear of the virus.C. They showed the world how to produce a vaccine.D. They invited collective efforts worldwide to develop a vaccine.23. What is the authors purpose of mentioning remdesivir in the text?A. To introduc
19、e a possible cure for the epidemic.B. To compare the treatment of Ebola and the novel coronavirus.C. To prove that many drug companies readily share their discoveries.D. To show that the novel coronavirus will soon be contained.24. What does the underlined word critical in paragraph 5 probably mean?
20、A. expressing disapproval. B. extremely important.C. serious, uncertain and possibly dangerous. D. making fair, careful judgments.25. Which of the following would Dan Barouch probably disagree with?A. Epidemics will be less frequent thanks to scientific development.B. The world is becoming better pr
21、epared to deal with epidemics.C. No single group can fight against the epidemics independently.D. The increase in globalization may worsen future epidemics.BLight and bright, cheap and cheerful: IKEAs 400-plus outlets(专营店)in 49 countries all run on the same central principle. Customers do as much of
22、 the work as possible, in the belief they are having fun and saving money. You drive to a distant warehouse built on cheap out-of-town land. Inside, you enter a maze(迷宫)-no shortcuts allowed-where every twist reveals new furniture.Compared with the prices of other outlets, IKEAs are much lower. You
23、load up your trolley(手推车)with impulse buys-a clock, storage boxes, tools and more chairs than you will ever use. You drag cardboard boxes, cupboards and tables into your car and reward yourself for your economy and good taste. Then you drive home and put your prizes together. You are satisfied with
24、the bargains. IKEA is satisfied with your money.The companys name was a do-it-yourself job, too. IKEA stands for Ingvar Kamprad, from Elmtaryd-his familys farm-in Agunnaryd. That village is in the Smaland region of southern Sweden. Mr Kamprad founded IKEA aged 17. Well before that, he spotted a prin
25、ciple which would make him one of the richest men in the world that customers like buying goods at wholesale prices(批发价). First he bought matches in large quantities and sold them by the box. Aged ten, he sold pens in the similar way.Setbacks inspired him. Facing a price war against his low-cost mai
26、l-order furniture business, he defeated competitors by opening a showroom. Dealers tried to crush Mr Kamprad and banned him from their trade fairs. He slipped in, hiding in a friends car. When they tried to threaten his suppliers, he relied on his own workers, and secretly sold his production to com
27、munist Poland. Decades later, east Europeans freed from the planned economy drove hundreds of miles to newly opened outlets in Moscow and Warsaw.His self-discipline was world-famous. As a child, he removed the off button from his alarm clock to stop himself oversleeping. He rarely took a first-class
28、 seat. The wine didnt get you there any earlier, he sniffed; having lots of money was no reason to waste it. He bought his clothes in second-hand markets, and for years drove an elderly Volvo until he had to sell it on safety grounds. He had his hair cut in poor countries to save money. Visitors adm
29、ired the views, but were surprised that his house was so shabby. He worked well into his eighties.His diligence and simple way of life set a good example to his 194,000 co-workers. But he was not mean. The point of cutting costs was to make goods affordable, not to compromise quality. He urged his s
30、taff to reflect constantly on ways of saving money, time and space. An improved design that allows easier piling means shipping less air-and more profit.Culture was more important than strategy. He disliked exaggerated(夸张的)planning, along with financial markets and banks. Better to make mistakes and
31、 learn from them. And use time wisely: You can do so much in ten minutes. But ten minutes once gone are gone for good. This did not apply to customers. The longer they stayed, the better.Mr Kamprads impact on modern life can be compared with that of Henry Ford and the mass-produced motor car. Furnit
32、ure used to be expensive, dark and heavy. For many people, decorating a home could cost many months salary. IKEA made furniture not just affordable and functional, but fun. The mission was civilizational, he felt, changing how people lived and thought.His approach drew some fire. The company values
33、struck some as unpleasant. At IKEAs Corporate Culture Centre, lots of pictures of Mr Kamprad with his mottos can be seen everywhere. Whats worse, some parts of the supply chain seemed to have serious problems to overcome.26. What can we learn about IKEA in Paragraph 1?A. IKEA prefers rural areas for
34、 its location.B. IKEA has 400 outlets throughout the world.C. IKEA likes to store new furniture in a maze.D. IKEA provides a lot of work for its customers.27. The underlined two sentences in Paragraph 2 imply that .A. IKEA tricks you into spending more moneyB. you may buy bargains with impulse in IK
35、EAC. both you and IKEA are pleased with the dealD. both you and IKEA are happy with the bargain28. By mentioning Mr. Kamprads experiences before he founded IKEA, the author intends to tell us that Mr Kamprad .A. was likely to become a successful businessmanB. preferred selling matches and pens by lo
36、w pricesC. had been a well-off merchant due to his principleD. enjoyed doing something promising with discipline29. What can be inferred from paragraph 5 and 6 about Mr. Kamprad?A. He never overslept due to his alarm clock being set.B. He was against drinking but for sniffing at the wine.C. He sold
37、the old Volvo with the purpose of saving money.D. He didnt give up the quality of furniture for more profit.30. Which of the following has nothing to do with Mr. Kamprads success in business?A. The pictures and mottos of Mr. Kamprad. B. The setbacks Mr. Kamprad experienced.C. Mr. Kamprads principles
38、 of management. D. Mr. Kamprads self-discipline and diligence.CIt was Saturday. As always, it was a busy one, for Six days shall you labor and do all your work was taken seriously back then. Outside, Father and Mr. Patrick next door were busy chopping firewood. Inside their own houses, Mother and Mr
39、s. Patrick were engaged in spring cleaning.Somehow the boys had slipped away to the back lot with their kites. Now, even at the risk of having Brother caught to beat carpets, they had sent him to the kitchen for more string(线). It seemed there was no limit to the heights to which kites would fly tod
40、ay.My mother looked at the sitting room, its furniture disordered for a thorough sweeping. Again she cast a look toward the window. Come on, girls! Lets take string to the boys and watch them fly the kites a minute.On the way we met Mrs. Patric, laughing guiltily as if she were doing something wrong
41、, together with her girls.There never was such a day for flying kites! We played all our fresh string into the boys kites and they went up higher and higher. We could hardly distinguish the orange-colored spots of the kites. Now and then we slowly pulled one kite back, watching it dancing up and dow
42、n in the wind, and finally bringing it down to earth, just for the joy of sending it up again.Even our fathers dropped their tools and joined us. Our mothers took their turn, laughing like schoolgirls. I think we were all beside ourselves. Parents forgot their duty and their dignity; children forgot
43、 their everyday fights and little jealousies. Perhaps its like this in the kingdom of heaven, I thought confusedly.It was growing dark before we all walked sleepily back to the houses. I suppose we had some sort of supper. I suppose there must have been surface tidying-up, for the house on Sunday lo
44、oked clean and orderly enough. The strange thing was, we didnt mention that day afterward. I felt a little embarrassed. Surely none of the others had been as excited as I. I locked the memory up in that deepest part of me where we keep the things that cannot be and yet they are.The years went on, th
45、en one day I was hurrying about my kitchen in a city apartment, trying to get some work out of the way while my three-year-old insistently cried her desire to go park, see duck.I cant go! I said. I have this and this to do, and when Im through Ill be too tired to walk that far.My mother, who was vis
46、iting us, looked up from the peas she was shelling. Its a wonderful day, she offered, really warm, yet theres a fine breeze. Do you remember that day we flew kites?I stopped in my dash between stove and sink. The locked door flew open and with it a rush of memories. Come on, I told my little girl. Y
47、oure right, its too good a day to miss.Another decade passed. We were in the aftermath(余波)of a great war. All evening we had been asking our returned soldier, the youngest Patrick Boy, about his experiences as a prisoner of war. He had talked freely, but now for a long time he had been silent. What
48、was he thinking of- what dark and horrible things?Say! A smile slipped out from his lips. Do you remember-no, of course you wouldnt. It probably didnt make the impression on you as it did on me.I hardly dared speak. Remember what?I used to think of that day a lot in POW camp(战俘营), when things werent
49、 too good. Do you remember the day we flew the kites?31. Mrs. Patrick was laughing guiltily because she thought .A. she was too old to fly kitesB. her husband would make fun of herC. she should have been doing her housework D. her girls werent supposed to join the boys games32. By we were all beside
50、 ourselves writer means that they all .A. felt confused B. went wild with joy C. looked on D. forgot their fights33. What did the author think after the kite-flying?A. The boys must have had more fun than the girls.B. They should have finished their work before playing.C. Her parents should spend mo
51、re time with them.D. All the others must have forgotten that day.34. Why did the writer finally agree to take her little girl for an outing?A. She suddenly remembered her duty as a mother.B. She was reminded of the day they flew kites.C. She had finished her work in the kitchen.D. She thought it was
52、 a great day to play outside.35. The youngest Patrick boy is mentioned to show thatA. the writer was not alone in treasuring her fond memoriesB. his experience in POW camp threw a shadow over his lifeC. childhood friendship means so much to the writerD. people like him really changed a lot after the
53、 war第二节(共5小题;每小题2分,满分10分)根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。Things only people who have worked overseas can understandIf you have ever worked or lived overseas, Im pretty sure you can understand the following things!We do not automatically become fluent in another language. A lot of people bel
54、ieve that changing your geographic location can improve your language learning skills quickly. 36 Language application takes time and has a number of factors that play into a persons level of fluency.We feel extremely lonely at times. Yes, living abroad can be wonderful. 37 Sometimes, we think that
55、no one back at home understands our true feelings and life challenges, but a lot of other people travel long term and work abroad. Maybe they are not facing the same problems as you, but they know exactly how you feel.We dont really like our birthdays. Usually, your special day ends with the last ph
56、one call you get from home and then you can look through all your greetings on social media. 38 You may throw a small party with some of your new friends, but its going to be nothing compared with the good-old feasts you used to have with your loved ones back at home. 39 Too often we simply cant tel
57、l you if we will be coming home for holidays this season. Sometimes, our working/living permits require us to stay in the country for at least a year. Adding up the flight costs and additional travel expenses, traveling home becomes quite a challenge for us.We will change. 40 You become more mature,
58、 independent and open-minded. Usually, you return home as a better person than the one you left as.A. The truth is: it isnt like that.B. We may not plan to move back home.C. We dont know when well come home next.D. However, it can get extremely lonely on some days too.E. Living abroad makes us value
59、 the little things a lot.F. Living and working abroad shape your personality a lot.G. After that, you just act as if its another ordinary day in your life yet.第三部分 完形填空(共15小题;每小题1分,满分15分)阅读下面短文,从短文后各题所给的A、B、C和D四个选项中,选出可以填入空白处的最佳选项,并在答题卡上将该项涂黑。Ten years ago, I set out to examine luck. I wanted to kno
60、w why some people are 41 in the right place at the right time, while others consistently experienced ill fortune. I placed 42 in national newspapers asking for people who felt consistently lucky or unlucky to 43 me.Hundreds of extraordinary men and women volunteered for my research. Over the years I
61、 interviewed them, watched their lives and had them 44 various experiments.I carried out a simple experiment to discover whether their differences in 45 was due to differences in their ability to 46 opportunities. I gave both lucky and unlucky people a newspaper, and asked them to 47 it and tell me
62、how many photographs were inside. I had 48 placed a large message halfway through the newspaper saying Tell the experimenter you have seen this and win $ 50.This message took up half of the page and was written in type that was more than two inches high. It was staring everyone straight in the face,
63、 but the unlucky people tended to 49 it and the lucky people tended to spot it.Unlucky people are generally more 50 than lucky people, and this anxiety affects their ability to notice the 51 . As a result, they miss opportunities because they are too focused on looking for something else. They go to
64、 gatherings focused on finding their perfect partner and miss opportunities to make good friends. They read newspapers. 52 to find certain types of job advertisements and miss other types of jobs.Lucky people are more 53 we and open, and therefore see what is there rather than just what they are loo
65、king for. My research eventually showed that lucky people create good fortune via four 54 . They are skilled at creating and 55 opportunities, make lucky decisions by listening to their intuition(直觉), create self-fulfilling prophesies(预言)via positive expectations, and adopt a never say die attitude
66、that transforms bad luck into good.41. A. never B. always C. sometimes D. seldom42. A. messages B. activities C. reports D. notices43. A. contact B. trust C. show D. follow44. A. participate in B. learn about C. look into D. carry out45. A. attitude B. manner C. lifestyle D. luck46. A. share B. spot
67、 C. create D. predict47. A. look through B. put through C. get through D. see through48. A. hesitantly B. carelessly C. secretly D. excitedly49. A. pass B. miss C. notice D. misunderstand50. A. nervous B. violent C. awkward D. pitiful51. A. difficult B. dangerous C. important D. unexpected52. A. con
68、fident B. disappointed C. determined D. surprised53. A. reliableB. hardworking C. smart D. relaxed54. A. goalsB. preferences C. principles D. steps55. A. inventingB. noticing C. taking D. adopting第II卷(非选择题,共75分)第四部分 语法填空(共10小题;每小题1.5分,满分15分)阅读下面短文,在空白处填入适当的词,如有括号提示,请以提示词的正确形式填空。请将答案的完整形式写在答题卡上相应题号的横
69、线上。The Chinese Garden of Friendship was built as a beautiful symbol of friendship56. Sydney in the State of New South Wales and Guangzhou in the province of Guangdong, China(sister cities of sister states), to mark Australias bicentenary(二百周年纪念)in 1988.The garden 57. (design) and built by Chinese la
70、ndscape architects and gardeners, 58. (follow) the Taoist principles of Yin-Yang and the five opposite elements- earth, fire, water, metal and wood. These principles also stress the 59. (important) of Qi, the central force of life and energy.Yin-Yang 60. (play) such a vital role that just one missin
71、g element would disrupt the gardens harmony and balance. However, when 61. (combine) perfectly, the five elements form a fluid and nurturing environment. Everything you encounter in the garden has been hand-picked and very carefully placed to capture the five elements and the energy of Qi.Unlike wes
72、tern-style gardens, there are no planted flowerbeds 62. neatly-cut lawns, wild 63. (aspect) of nature are recreated in landscapes 64. feature waterfalls, mountains, lakes and forests.The art of Chinese Garden design began in imperial parks during the Shang Dynasty 3,000 years ago. Darling Harbors Ch
73、inese Garden of Friendship is a small-scale version of 65. (type) private garden from this time.第五部分 词汇检测(共10小题;每小题1分,满分10分)请认真阅读下列各小题,并根据上下文语境和所给首字母或中文的提示,写出下列各句空格中的单词,注意保持语义和形式的一致。请将答案的完整形式写在答题卷上相应题号的横线上。66. Successfully applied, new technologies can a a countrys development and help transform man
74、y aspects of peoples daily life.67. With sit-down exams now impossible, Ms Huang believes that students should be e in terms of their performance in classroom discussions during live streams.68. The house, which was once the birthplace of the general, was found a after a severe fire.69. Coronaviruse
75、s can cause a range of s varying from common cold to more serious respiratory illnesses.70. The Presidents tour was characterized by a t schedule and rich contents. During the 8-day tour, he visited 5 countries, attended 2 meetings and participated in more than 70 activities.71. Video games can be f
76、un and exciting, but we need to look out when this pastime becomes a(n) (上瘾).72. Drivers who are too (争强好胜的)are the major cause of traffic jams, because of their habits of driving too fast and frequently slamming on the brakes.73. Fluency and (准确)are two factors which determine the success of the st
77、udents learning a second language in the future.74. On April 4th, 2020, China held a national mourning for martyrs(烈士)who (牺牲) their lives in the fight against the epidemic.75. Many coffee drinkers in China have been in a panic that coffee causes cancer after a post was (传播)on social media on the we
78、ekend.第六部分 短语填空(共10小题;每小题1分,满分10分)请认真阅读下列各小题,并根据上下文语境,从方框中选择适当的短语(有两个多余选项),并以其正确的形式填空使语义完整。注意:请将答案的完整形式写在答题卷上相应题号的横线上。under the authority ofwind upturn tocorrespond toarise frombenefit fromchoke backmake reference tolet outaddress oneself toequip oneself withsubscribe to76. A young nurse couldnt her
79、 tears as patients bowed in farewell to medical workers before leaving the hospital.77. Nowadays, some people have changed the approaches to newspapers, magazines and other reading materials.78. She likes having the car windows when driving.79. It is reported that the train lines were placed the Boa
80、rd.80. A Chinese exchange student a full year of overseas living experience in the US, which improved his ability to work and live independently.81. Our time is running out, so it is time we the business in hand.82. The experts mentioned that some mistakes a basic misunderstanding at the conference.
81、83. On the release conference of the new product, the manager the long-term research conducted on this product, which made the audience totally satisfied.84. The former president Obama once encouraged teenagers to go all out for a better future and get prepared for SAT, GaoKao in China when he addre
82、ssed all the students at Wakefield High School in Arlington, Virginia.85. At first, many major platforms for online classes were tested, yet none of them turned out to be good enough. Then, I urged myself to think outside of the box and decided to trusty Wechat for a possible solution.第七部分 书面表达(共两节,
83、满分40分)第一节 应用文写作(满分15分)随着手机及其他电子设备的普及,“低头族”随处可见。大街上,公交车上,以年轻人为主。针对这一问题,请写一篇倡议书,提醒人们低头看手机的危害,并呼吁人们尽量抬起头来。要求:1、观点鲜明;2、行文连贯流畅;3、字数100左右。文章开头已经给出,不计入总词数。参考词汇:低头族phubberThe mobile phone and other electric devices have been part of our life, bringing us convenience. However, more and more phubbers, especia
84、lly young people, bury themselves in their phones without looking at what was going on around them. 第二节 概要写作(满分25分)阅读下面短文,根据其内容写一篇60词左右的内容概要。Emotional eating is when people use food as a way to deal with feelings instead of satisfying hunger. Believe it or not, weve all been there. Have you ever fin
85、ished a whole bag of chips out of boredom or downed cookie after cookie while preparing for a big test? But when done a lot-especially without realizing it-emotional eating can affect weight, health and overall well-being.Not many of us make the connection between eating and our feelings. Understand
86、ing what drives emotional eating can help people take steps to change it. One of the biggest myths about emotional eating is that its caused by negative feelings. Yes, people often turn to food when theyre stressed out, lonely, sad, anxious or bored. But emotional eating can be linked to positive fe
87、elings too, like the romance of sharing dessert on Valentines Day or the celebration of a holiday feast. Sometimes, emotional eating is tied to major life events, like a death or a divorce. More often, though, its the countless little daily stresses that cause someone to seek comfort in food.Emotion
88、al eating patterns can be learned. A child who is given candy after a big achievement may grow up using candy as a reward for a job well done. If a crying boy gets some cookies, he may link cookies with comfort. Its not easy to unlearn patterns of emotional eating. But it is possible. And it starts
89、with an awareness of whats going on.Were all emotional eaters to a degree. But for some people, emotional eating can be a real problem, causing serious weight gain or other problems. The trouble with emotional eating is that once the pleasure of eating is gone, the feelings that cause it remain. And you often may feel worse about eating the amount or type of food you like. Thats why it helps to know the difference between physical hunger and emotional hunger. Next time you reach for a snack, wait and think about which type of hunger is driving it. - 19 - 版权所有高考资源网