资源简介 七年级参考答案及听力材料(2025.01)参考答案一、听力1-5 BBCBA 6-10 BCAAB 11-15 AAACC 16-20 BCCAC二、单项选择21-25 AABBD 26-30 CCDCB三、完形填空31-35 ABDAB 36-40 CDDCB 41-42 CA四、阅读理解43-47 BBAAC 48-52 CCBCD 53-57 BBDBA 58-62 ADCAB五、任务型阅读63. health 64. Make 65. how 66. Remember 67. hard/difficult68. best 69. follow 70. Trying 71. small/smaller 72. like六、短文填空73. for 74. has 75. because 76. first 77. their78. go 79. carefully 80. colourful 81. Children 82. an七、翻译句子(每根下划线所示语言点 0.5分)83. The elders give us lucky money in the hope of bringing us good luck.84. White has a clean look/looks clean and it can match/go well with/go together with any other color.85. As a fan of science, he likes to take things apart and learn how they work.86. This modern lab is a perfect place to learn biology.八、句型转换87. doesn’t, any 88. is, with 89. pay for//spend on/buying 90.stands, out九、书面表达My good habitsGood habits play an important role in everyone’s life. I’d like to share some of my good habitswith you.I have good learning habits. At the beginning of each term, I make a study plan. I always finishmy homework on time and after finishing it, I often read some interesting books. I believe reading canmake me know more about the world.Another habit that I have is a healthy lifestyle. I get up early every morning and never stay uplate. Also, I do some exercise like running or playing basketball for half an hour every day.What’s more, I have wise spending habits. I never spend money on useless things. I save some inthe bank because it’s a good idea to save for a rainy day.These good habits help me become better and I believe with the good habits by my side, I willhave a brighter future.My good habitsGood habits play an important role in everyone’s life. I’d like to share some of my good habitswith you.I have healthy living habits. A healthy diet with more fruit and vegetables helps me stay fit. I alsogo to bed early and make sure I have 9 hours of sleep every day. A healthy lifestyle makes me full ofenergy.I also have good habits of spending money wisely. I usually think twice before buying. I alsosave some in the bank because you never know when you may need it. Wise spending habits make mefeel safe and I can even do something good for others with the money.Doing chores helps me get some important life skills as well. After finishing my homework, Ialways put away my school things. I also help my mom wash the dishes and empty the bins. Everytime I see my tidy room, I feel really happy because through these daily chores, I find I can also takecare of my family.写作评分说明第五档文(9-10 分):准确理解写作任务;文章长度符合要求、书写规范、要点齐全、层次清楚、逻辑严密语言流畅,句式丰富;基本无语法错误,或有少量由于使用复杂结构而引起的语法或拼错误,但不影响意义理解。第四档文(6-8 分):理解写作任务;文章长度符合要求、书写规范、要点基本齐全、层次清楚、语言流畅有少量语法错误(3-4 个错误)。第三档文(4-5 分):文章长度与要求有差距、写出大部分内容要点,语言基本通顺,有一些语法和拼写错误,基本不影响意思表达。第二档文(2-3 分):文章长度与要求有明显差距、写出一半左右有关内容要点,语言不太通顺,语法结构单调、错误较多,只有少数句子可读,影响理解。第一档文(0-1 分):言不达意,不知所云;只有 2-3 个短语可读。听力材料第一部分 听对话回答问题本部分共有 10道小题,每小题你将听到一段对话,每段对话听两遍。在听每段对话前,你将有5秒钟的时间阅读题目;听完后,你仍有 5秒钟的时间答题。1. M: Is the woman with glasses our new English teacher W: No. She is Simon’s aunt.2. M: What time do you get up W: Usually I get up at seven fifteen, but today I get up at seven o’clock.3. M: Is Music your favourite subject W: No. My favourite subject is Geography.4. M: Is David playing football in the playground W: No. He is running.5. W: How many boys and girls are there in class Two M: There are 24 boys and 19 girls in it.6. M: Do you practise table tennis every afternoon, Amy W: Yes. I come here at 4:30 p.m. and have to go home at 6:00 p.m.7. M: Cindy , which vegetable do you like W: I like carrots and my mother likes them too.8. M: Hey, May. Our new classroom building has four floors and looks bright.W: Yes. My classroom is on the second floor. What about yours M: Mine is on the same floor as yours.9. M: Does this brown shirt look good on me W: Yes. The shirts are very cheap. Two of these only cost one hundred yuan.10. M: How beautiful the paper-cut is!W: Yes. Making the paper-cut sounds easy but it can be difficult to do. I can only make someeasy ones.听对话和短文答题你将听到一段对话和两篇短文,各听两遍听一段对话,回答第 11- 12 小题。W: Mandy is wearing my design for the fashion show. Does she look smart, Jack M: Yes. I like her yellow T-shirt. The picture on it is really special.W: I draw it myself. The T-shirt is made of cotton, so it’s very soft.M: And blue jeans are popular with young people.W: Right. Blue is a calm colour. I like wearing blue in summer.M: You are a perfect fashion designer, Linda.听第一篇短文,回答第 13-15小题。请根据短文内容,选择正确答案,完成信息记录表。Do you know John Smith He is an old Music teacher. He is busy but happy every day. He usuallygets up at half past six every morning and jogs for half an hour. He says jogging helps make himhealthy. After that, he has breakfast. Bread and juice are his favourite. In the afternoon, his friendsoften come to talk about music with him. They have a good time. Then, he sleeps for a short time. At6:00 p.m., he cooks for his family. In the evening, he always does some reading from 7:00 p.m. He isinterested in reading all kinds of books. He thinks he can learn more about the world in this way.听第二篇短文,回答第 16-20小题Today is Friday. It’s seven o’clock in the morning.Mr Brown is sitting near the window of the livingroom. Mrs Brown comes in from the kitchen with a cup of coffee in her hand. She stands behind herhusband and says, “What are you doing ”“I’m looking at a boy,” Mr Brown answers. “He’s under thetree in our garden, and he is looking at my bike.”“What’s he doing now ” Mrs Brown asks.“He iscleaning the seat,” says Mr Brown. “Now he is riding my bike.”Mrs Brown looks out of the windowand says, “Oh, don’t you know that boy He’s Jack, our son. He is going to school. That’s his bike.You must wear your glasses.”2024-2025 学年度第一学期期末调研测试试卷七年级英语(考试时间:120分钟 满分:100分)第一部分 选择题(共 62分)一、听力(本题共 20小题;每小题 1分,共 20分)第一部分 听对话回答问题本部分共有 10道小题,每小题你将听到一段对话,每段对话听两遍。1. What does Simon’s aunt look like A. B. C.2. When does the girl get up today A. B. C3. What is the girl’s favourite subject A. B. C.4. What is David doing now A. B. C.5. How many students are there in Class 2 A. 43. B. 24. C. We don’t know.6. How long does Amy practise table tennis every day A. For half an hour. B. For one and a half hours. C. For an hour.7. Who likes to eat carrots A. Cindy B. Cindy’s mother. C. Cindy and her mother.8. Which floor is the boy’s classroom on A.The second floor. B. The third floor. C. The fourth floor.9. How much is a shirt A.50 yuan. B. 100 yuan. C. 200 yuan.10. What does the girl think of the paper-cut A.It’s easy to learn. B. It’s difficult to learn. C. It’s boring to learn.第二部分 听对话和短文答题听一段对话,回答第 11—12 小题。11. Who draws the picture on the T-shirt A. Linda. B. Mandy. C. Jack.12. What colour does Linda like wearing in summer A. Blue. B. Yellow. C. Green.听第一篇短文,回答第 13—15小题。请根据短文内容,选择正确答案,完成信息记录表。John Smith’s day● 13 for half an hourIn the morning●having breakfast● 14 about music with friendsIn the afternoon●sleeping for a short timeIn the evening ●starting to read at 1513. A. jogging B. swimming C. skating14. A. writing B. reading C. talking15. А. 6:00 p.m. B. 6:30 p.m. C. 7:00 p.m.听第二篇短文,回答第 16—20小题16. When does the story happen?A. On Monday afternoon. B. On Friday morning. C. On Monday morning.17. Where is Mrs. Brown now A. In the garden. B. In the kitchen. C. In the living room.18. Where is the boy in the garden A. Behind Mrs. Brown. B. In the tree. C. Under the tree.19. What’s the boy doing in the garden A. He’s riding a bike. B. He’s sitting on the grass.C. He’s having a cup of coffee.20. What can we know from the talk A. Mr. Brown doesn’t know the boy. B. That bike in the garden is Mr. Brown’s.C. Mr. Brown can’t see very well without glasses.二、单项选择 从下列每题所给的选项中,选择一个最佳答案。(本题共 10小题,每小题 1分,共 10分)21. I often go to Mr. Shepherd’s office to ask________some English questions, but sometimes he isn’t in.A. him B. her C. you D. his22. Girls in our class show interest in ________. Some like painting and others like dancing.A. art B. sport C. fashion D. culture23. In the following words, which underlined (划线的) letter has a different sound from the others A. euro B. dollar C. joke D. kilo24. The world’s largest Ice-and-Snow Theme Park(冰雪主题公园) opened _________the morning ofDec.21, 2024 in Harbin.A. in B. on C. at D. between25. — ________ do you plan to do for the winter holiday, Tom — I have no idea. Maybe I’ll go to Hainan with my family.A. How B. When C. Why D. What26. — You look very tired after finishing all of those hard jobs.— Yes. I’ll take a rest and make myself ________.A. suitable B. polite C. comfortable D. sweet27. — You ________, Frank. Don’t talk on the phone.— Sorry, I’ll hang up right now.A. will drive B. drive C. are driving D. were driving28. — Dr. Smith, my son spends too much time on the computer. What should I do — Do different activities with him, and he may not ________ the computer too much.A. get over B. leave for C. look up D. depend on29. Students in Class 3 do a survey on the ways to have fun in their free time.The pie chart tells us that _______________________.A. 25% of the students would like to exerciseB. 10% of the students like listening to musicC. reading books is the most popular way to relaxD. most students choose other ways to have fun30. — I really enjoy reading science books. They take me to amazing worlds.— ________. The cool ideas and strange places always make me interested.A. Here you are B. Same here C. That’s all right D. Not really三、完形填空 阅读下面短文,从每题所给的 A、B、C、D四个选项中选出可以填入空白处的最佳选项 。(本题共 12小题;每小题 1 分,满分 12分)I am enjoying a book when my wife calls me to help our neighbour, Mrs. White.I open the front door and seeMrs.White sitting on her chair and 31 her garden.“Ah, Tom! Good to see you!” she greets me 32 . “A beautiful morning,isn’t it ”“Err, yes, it is,” I say. I don’t knowwhy she is so happy because she is ill and cannot walk these days.“Look at those dandelions(蒲公英)in my garden. What a perfect symbol of 33 !”“Happiness... ” I look around and only see weeds(野草)...“Look at that bright beautiful 34 colour! It’s a happy colour! And the dandelion 35 justlike happiness. If you are really happy, you will bring happiness to the people around you. Then theybecome happy, and they will do the same. 36 , the happiness goes around you. You see, when theseeds(种子) of dandelions go into the wind, you will see a thousand sunny little flowers around you. Eachdandelion is like a sun!”“But it is a weed...” I say.“A weed that’s funny. I’m always watching people work on their garden. 37 I seldom seethem sit and just look at their beautiful garden. They just work on it and don’t 38 it.”Well... she is right. I 39 hear anyone talk about the beauty of their garden.They only findit is so 40 to work on it.And then I hurry into my house and 41 what she says on the first page of my book.“What a bad day, they say. But I look at the dandelions and see a thousand little 42 .”31. A. watching B. decorating C. growing D. respecting32. A. sadly B. excitedly C. calmly D. quietly33. A. sadness B. hope C. surprise D. happiness34. A. yellow B. blue C. black D. green35. A. smells B. spreads C. leaves D. begins36. A. On the way B. By the way C. In this way D. Across the way37. A. So B. Because C. And D. But38. A. miss B. carry C. want D. enjoy39. A. often B. always C. never D. usually40. A. wise B. tiring C. formal D. casual41. A. care about B. hope for C. write down D. take part42. A. suns B. moons C. plants D. lanterns四、阅读理解 阅读下列短文,根据内容选择正确答案。(本题共20 小题;每小题 1 分,满分 20 分)AThis year, we have some new sports and games for you to take part in.The sports you can choose to join in:●Basketball●Tennis●Skateboarding(滑板)●RunningThe study classes you can sign up(报名):●Tae kwon do(跆拳道)●Volleyball●Long jump●Table tennis Study classes will teach you about the history of each sport and how to do it. If you are a fan of sport, don’t wait and call us on 8998666 or email us at stpauls@ toget your first pick. You can also sign up right here at our library. Get your parents’ agreement first. The deadline(截止时间) for signing up is June 14.43. When is St. Paul’s School Sports Day A. On June 14. B. On June 15. C. On July 14. D. On July 15.44. What sports can the students choose to join in ① Running. ② Tennis ③ Skateboarding ④Tae kwon do ⑤BasketballA.①②③④ B.①②③⑤ C.①③④⑤ D.②③④⑤45. Students CAN’T sign up for the Sports Day by __________.A. writing a letter B.sending an e-mail C. going to the library D. making a phone call46. Simon signs up for the study classes. What can he do on the Sports Day A. Learn skills of playing volleyball. B. Have free lunch before 10 a.m.C. Show his parents around school. D. Learn the history of skateboarding.47. Where can we most probably (可能) read this text A. In a history magazine. B. In a tour newspaper.C. On a noticeboard. D. In a story book.BThere is a circle(圆圈) living in a forest. One day, he finds a pieceis missing(丢失的). He wants to find it back, so he goes around andlooks for it. But because he isn’t round, he can’t go very quickly.On the way, the circle sees many beautiful things. There are somany beautiful flowers in different colours and they smell reallygood. ① The circle stops and looks at them one by one. He alsotalks with the birds in the trees. The sunshine is warm and makes himfeel comfortable. And he also finds many pieces. ② But theydon’t fit. He leaves them all by the side of the road and keeps on going.One day, he finds a good piece. ③ It fits well. The circle is very happy and puts the piece in.He can go quickly now, but he can’t enjoy the flowers. He can’t talk with birds, either. The circle feelsvery sad.After that, he has a good idea. He leaves the piece by the side of the road. He goes slowly again toenjoy many beautiful things. ④ Sometimes, he stops to watch a little rabbit hopping(跳跃) around.He also listens to the soft wind blowing through the grass. At last, he lives a wonderful life.48. What does the underlined word “it” in the first paragraph refer to(指代) A. The circle. B. The flower. C. The piece. D. The bird.49. Some pieces don’t fit. What does the circle do with them A. Try to change them. B. Take them with him.C. Put them by the road. D. Give them to others.50. Where should we place the sentence “He picks them up and tries to put them back. ” in the text A. ① B. ② C. ③ D. ④51. What does the circle do to have a wonderful life at last A. Keep the piece and go quickly. B. Look for more pieces to be perfect.C. Leave the piece and enjoy slowly. D. Ask the birds and animals for help.52. What can we learn from this story A. We must always try to be perfect. B. It’s better to be fast than to be slow.C. A man who has everything is the happiest. D. Losing something may not be bad sometimes.COne sunny morning, Bingo, a farm dog, wakes up at 5:30. After having aquick breakfast, Bingo starts his work. He first goes to the sheep’s house. Healways helps the farmer Joe lead(带领) the sheep across the fields, so Bingo isreally popular with the sheep. Bingo runs happily and goes around the sheep asthey eat grass in the fields.At about a quarter to eleven, the sheep finishes eating, and then Bingo leadsthem back to the house. Next, he goes to the chickens’ house. He watches the chickens peck(啄食)attheir food. Sometimes, a few chickens go too far from the house. With a gentle bark(犬吠), Bingo callsthem back.Two hours later, Bingo rests under a tree and watches the cows eat the green grass. But his restdoesn’t last long. Soon he hears Joe calling,“Bingo! I need your help!”Bingo jumps up and runs quickly to Joe. Joe is trying to fix an old fence(篱笆). Without some partsof the fence, the cows get too close to the road. Bingo knows what to do! He barks at the cows andquickly leads them back to the safe place.As it’s getting dark, Bingo goes back to his bed. He spends the whole day helping his animal friendsand working with Joe. The friendly dog is tired but happy!53. The sheep like Bingo because he always_______________.A. brings them breakfast B. leads them across the fieldsC. plays with them every day D. protects them from other animals54. What happens when some chickens go too far A. Bingo runs to tell the farmer. B. Bingo barks gently to call them back.C. The farmer comes and takes them back. D. The other chickens go to bring them back.55. Joe calls Bingo because he needs Bingo to help him______________.A. play with the cows B. fix the old fence togetherC. lead the cows across the road D. lead the cows back to safety56. Read the following events and put each event in the right box on the time line. Which one is right Early morning Late morning Afternoon Evening ①Bingo goes to the sheep’s house and leads them to the fields.②Bingo takes the sheep back to the house after they finish eating.③Bingo watches the chickens and brings those far away back.④Bingo rests under a tree when the cows eat grass.⑤Bingo helps Joe drives the cows back.⑥Bingo goes back to his bed, feeling tired but happy.A.①②→③④→⑤→⑥ B.①→②③→④⑤→⑥C.①②→③→④⑤→⑥ D.①→②③④→⑤→⑥57. What’s the best title (标题) for the passage A. Bingo’s busy day B. Life on a farmC. Joe and his farm dog D. A happy dogD①What colour are blueberries Blue, of course! But guess what The berry’scolor is not “true blue”. It just looks blue to our eyes because of a waxy coating(蜡质涂层). If you rub this coating off(擦掉),the blueberry will not look blue. In fact, it’sdark, says scientist Rox Middleton.②Blue is not a usual color in nature. Less than one in ten plants are blue. Why To answer this question, we should know the fact—there is no true blue pigment(色素) in nature.③So how does the blueberry do it First, the berry’s skin has a lot of anthocyanin. This kind ofpigment can look blue sometimes, but in blueberries, it looks dark red. Second, Rox’s team looks at theblueberry’s skin under a microscope(显微镜). What do they find The wax(蜡) on the skin has lots ofsmall parts. Each part is as thick as a piece of paper. These parts send back blue light. That’s why the fruitlooks blue to us.④The team of scientists hope to make materials to mimic(模仿)the waxy coating of blueberries.“This kind of colouring is cool because it is hard to wash away and you don’t need to worry about itgetting onto other colours of clothes.”58. When we rub off the waxy coating of a blueberry, the berry will look__________.A.dark B. red C.blue D. purple59. According to the article, less than__________percent of plants in nature are blue.A.one B. two C.five D.ten60. Why is blue an unusual color in nature A. Because blue pigments are easy to wash away.B. Because it is not as beautiful as any other color.C. Because there is no true blue pigment in nature.D. Because it is hard for plants to make blue pigments.61. The word“anthocyanin”in paragraph ③ is a kind of ______.A. pigment B. fruit C. berry D. paper62. What can we infer(推测) from paragraph ④ A. People like to mix different colours together.B. Some special features of things can bring good ideas.C. Making new materials is a very easy thing for scientists.D. People don’t like blueberries because it’s not a “true blue”.第二部分 非选择题(38分)五、任务型阅读 阅读下面的短文,并根据所读内容在文章后图表中的空格里填入一个最恰当的单词,每个空格只填一个单词。(本题共10 小题;每小题 1 分,满分 10 分)Do you sometimes look at your parents and wish they are healthier We doa survey of some kids, and the survey shows that 46% say they worry about theirparents, 69% of the kids would like their parents to make some changes to theirlifestyle to be healthier. Here are the tips on talking to your parents about this.▲ Make a listDoes your dad smoke or does your mum go to bed too late Do you want them to have a healthyway of living such as exercising or eating fruit and vegetables more often Make your list together. Anddon’t forget the two great and healthy ideas—relaxing more and sleeping more.▲Practise how to say itChanging can be hard. And it’s not always easy to hear someone ask you to change. So you shouldsay it in a polite way. Put yourself in others’ shoes. If your parents want you to make a change, howwould you like them to ask A gentle and caring way often works best.▲Decide togetherIf you talk about it with your parents, both you and your parents should make a plan and followit. It’s better to choose just one goal(目标). If you try to make a lot of changes at the same time, thingswill go wrong. If your goal is too big, you won’t know what you should do first and soon youwill lose heart.▲Cheer them onCheer for your parents as they start making changes. Your care such as a hug(拥 抱 ) or ahand-made card can help them keep going along the healthy road.Help your parents keep healthy46% of kids worry about their parents’ 63 .About the survey69% of the kids want their parents to change their lifestyle.Think about 65 your parents live their life.64 a list66 the two great and healthy ideas—relaxing more and sleeping more.It’s 67 for people to make a change. So put yourself in others’ shoes.Practise how to say itA gentle and caring way often works 68 .You and your parents must make a plan together and 69 it.Decide together 70 to make a lot of changes at the same time is wrong.Make you goal 71 , and you may know what to do first.With your care 72 a hug or a card full of love, your parents will keepCheer them ongoing along the healthy road.六、语篇填空 阅读下面的短文,在空白处填入适当的单词或括号内单词的正确形式。有提示词的空格不限一词,无提示词的空格限填一词。(本题共10 小题;每小题 1 分,满分 10 分)The Chinese character(汉字) Fu is special in Spring Festival celebrations. It showspeople’s best wishes 73 good luck and happiness. The tradition of putting up thecharacter Fu on walls and windows 74 (have) a long history. People can put upthe character Fu either right-side up or upside down(颠倒), 75 in Chinese, the“upside-down Fu” and “Fu arrives” sound similar. Both of them are “Fu dao le”.There is a story about the “upside-down Fu”. Zhu Yuanzhang, the 76 (one) emperor(皇帝)of the Ming Dynasty, used “Fu” as a sign to kill(杀死) a family. To save the family, Empress(皇后) Maasked all the families to put up “Fu” on 77 (they) front doors. One family put it upside downbecause they couldn’t read or write. The emperor was angry but Empress Ma said it meant “Fu arrives”.After hearing this, Zhu Yuanzhang was happy and let the family 78 (go). After that, more andmore people start to put up the “Fu” character upside down when the Spring Festival comes.When people put up the “Fu” character, they always do it 79 (careful). They believe bydoing this, good luck will come to their homes. It makes the Spring Festival more lively and 80 (colour).As the red “Fu” characters carry people’s best wishes, 81 (child) also like to look at theupside-down “Fu” and listen to the story. Are you excited about the coming Spring Festival Maybe youcan also try to put up 82 upside-down “Fu” by yourself.七、翻译句子 (本题共 4小题;每小题 1 分,共 4 分)83. 长辈们给我们压岁钱,希望给我们带来好运。_________________________________________________________84. 白色看起来很干净,而且可以搭配其他任何颜色。_________________________________________________________85. 作为一个科学迷,他喜欢把东西拆开并研究它们是怎么工作的。_________________________________________________________86. 这个现代的实验室是一个学习生物的绝佳地方。_________________________________________________________八、句型转换(每空一词)(本题共4小题, 每空0.5分,共4分)87. Sam’s friend Tony does some sports every day.(改为否定句)Sam’s friend Tony __________do ___________sports every day.88. Our school has a big gym. It has three floors.(改为同义句)There_________ a big gym_________three floors in our school.89. This pair of trousers costs me 100 yuan.(改为同义句)I ________100 yuan ________this pair of trousers.90. The young lady wears a red coat in the fashion show so people can see her easily.(改为同义句)The young lady in a red coat___________ ___________in the fashion show.九、书面表达(共10分)91. 习惯是塑造我们日常生活乃至决定我们命运的无声力量。你校英语报正在举行主题为 My goodhabits的征文活动。请你用英语写一篇文章投稿,分享你至少两方面的好习惯(具体展开说明)以及从中获得的益处或感悟。写作要求:1. 以上图表内容仅供参考,可适当发挥;2. 词数 100左右,开头已给出,不计入总词数;3. 文中不得出现反映考生信息的真实人名、地名等内容。My good habitsGood habits play an important role in everyone’s life. I’d like to share some of my good habits withyou.____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 展开更多...... 收起↑ 资源列表 江苏省靖江市2024-2025学年七年级上学期1月期末英语试题.pdf 江苏省靖江市2024-2025学年七年级上学期1月期末英语试题听力.mp3 江苏省靖江市2024-2025学年七年级上学期1月期末英语试题答案.pdf