解析:①过原点时,直线方程为y=-34x.②直线不过原点时,可设其方程为xa+ya=1,∴4a+-3a=1,∴a=1.∴直线方程为x+y-1=0.所以这样的直线有2条,选B.答案:B4.若点P(3,m)在过点A(2,-1),B(-3,4)的直线上,则m= . 解析:由两点式方程得,过A,B两点的直线方程为(y"-(-" 1")" )/(4"-(-" 1")" )=(x"-" 2)/("-" 3"-" 2),即x+y-1=0.又点P(3,m)在直线AB上,所以3+m-1=0,得m=-2.答案:-2 5.直线ax+by=1(ab≠0)与两坐标轴围成的三角形的面积是 . 解析:直线在两坐标轴上的截距分别为1/a 与 1/b,所以直线与坐标轴围成的三角形面积为1/(2"|" ab"|" ).答案:1/(2"|" ab"|" )6.已知三角形的三个顶点A(0,4),B(-2,6),C(-8,0).(1)求三角形三边所在直线的方程;(2)求AC边上的垂直平分线的方程.解析(1)直线AB的方程为y-46-4=x-0-2-0,整理得x+y-4=0;直线BC的方程为y-06-0=x+8-2+8,整理得x-y+8=0;由截距式可知,直线AC的方程为x-8+y4=1,整理得x-2y+8=0.(2)线段AC的中点为D(-4,2),直线AC的斜率为12,则AC边上的垂直平分线的斜率为-2,所以AC边的垂直平分线的方程为y-2=-2(x+4),整理得2x+y+6=0.
【课件展示】《秦朝中央集权制度的建立》《教材简析》《教学目标》《教法简介》《教学过程设计及特色简述》【师】本节内容以秦代政治体制和官僚系统的建立为核心内容,主要包括秦朝中央集权制的建立的背景、建立过程及影响。本节内容在整个单元中起到承前启后的作用,在整个模块中也有相当重要的地位。让学生了解中国古代中央集权政治体制的初建对于理解我国古代政治制度的发展乃至我们今天的政治体制是十分必要的。 本堂课我采用多媒体和讲授法及历史辩论法相结合,通过巧妙设计问题情境,调动学生的学习积极性,使学生主动学习,探究思考。教师引导和组织学生采取小组讨论、情景体验等方式,达到教学目标。 本节内容分三个部分,下面首先看秦朝中央集权制度建立的前提即秦的统一
二、教学目标:1、知识与能力(1)了解我国古代冶金、制瓷、丝织业发展的基本情况;(2)了解中国古代手工业享誉世界的史实,培养学生的民族自信心。2、过程与方法(1)通过大量的历史图片,指导学生欣赏一些精湛的手工业艺术品,提高学生探究古代手工业的兴趣;(2)运用历史材料引导学生归纳古代手工业产品的基本特征。3、情感态度与价值观:通过本课教学,使学生充分地感受到我国古代人民的聪明与才智,认识到古代许多手工业品具有较高的艺术价值,以及在世界上的领先地位和对世界文明的影响,增强民族自豪感。
①2014年年中,世界卫生组织(WHO)公布了《2013年全球气候状况报告》。报告显示,2013年全球陆地和海洋表面平均温度为14.5℃,比1961-1990年的平均温度升高0.5℃。自有温度记录以来,全球14个最热年份中有13个出现在本世纪,而过去30年中每个10年都比前十年更热。②厄尔尼诺是发生在热带太平洋上海温异常增暖的气候现象,大范围热带太平洋增暖会造成全球气候变化。进入20世纪70年代后,全球出现的异常天气,都有范围广、灾情重、时间长等特点,而在这一系列异常天气的背后,厄尔尼诺暖流都起着重要作用。
⑦在仰韶文化时期,我国就有了对竹利用的确切记载。竹自竹简、珠笔到竹纸,在保存和传播我们中华民族的古老文化上立下了汗马功劳。以竹为题材的诗词歌赋,用竹编织和雕刻的艺术品,竹制的笙管笛箫奏出的音乐,无不给人类美的享受。⑧在我国文化史上,竹蕴含着中华民族重要的精神价值。人们在长期的劳动实践和文化活动中,把竹的生物特征逐渐升华为一种做人的美德。竹四季常青,不畏逆境,和松、梅并誉为“岁寒三友”;竹中空外直,虚怀若谷,和梅、兰、菊并称为“四君子”。⑨无论是魏晋嵇康、向秀等“竹林七贤”,还是唐朝李白、韩准等“竹溪六逸”,莫不对竹有一份执着和憧憬,清代郑板桥,与竹为邻,以竹为友,爱竹、写竹、画竹、赞竹。“千磨万击还坚韧,任尔东西南北风”,正是他坚忍不拔、超凡脱俗的人格写照。
青蒿素治疗疟疾效果显著,是抵抗疟疾耐药性最好的药物。中国发现青蒿素时,美国也研制出一种抗疟新药—化学合成的甲氟喹,但疟原虫很快就适应了它,产生耐药性,临床使用后患者还出现了明显的不良反应。而对于青蒿素这种从中草药中提取的药物,疟原虫对它完全没有抵抗能力。1976 年1月,柬埔寨爆发疟疾,因疟原虫已经产生耐药性,疫情一时难以控制。中国医疗队携带一批青蒿素在柬埔寨大显神威,挽救了一大批疟疾患者的生命。
本节课是新版教材人教A版普通高中课程标准实验教科书数学必修1第四章第4.3.2节《对数的运算》。其核心是弄清楚对数的定义,掌握对数的运算性质,理解它的关键就是通过实例使学生认识对数式与指数式的关系,分析得出对数的概念及对数式与指数式的 互化,通过实例推导对数的运算性质。由于它还与后续很多内容,比如对数函数及其性质,这也是高考必考内容之一,所以在本学科有着很重要的地位。解决重点的关键是抓住对数的概念、并让学生掌握对数式与指数式的互化;通过实例推导对数的运算性质,让学生准确地运用对数运算性质进行运算,学会运用换底公式。培养学生数学运算、数学抽象、逻辑推理和数学建模的核心素养。1、理解对数的概念,能进行指数式与对数式的互化;2、了解常用对数与自然对数的意义,理解对数恒等式并能运用于有关对数计算。
学生已经学习了指数运算性质,有了这些知识作储备,教科书通过利用指数运算性质,推导对数的运算性质,再学习利用对数的运算性质化简求值。课程目标1、通过具体实例引入,推导对数的运算性质;2、熟练掌握对数的运算性质,学会化简,计算.数学学科素养1.数学抽象:对数的运算性质;2.逻辑推理:换底公式的推导;3.数学运算:对数运算性质的应用;4.数学建模:在熟悉的实际情景中,模仿学过的数学建模过程解决问题.重点:对数的运算性质,换底公式,对数恒等式及其应用;难点:正确使用对数的运算性质和换底公式.教学方法:以学生为主体,采用诱思探究式教学,精讲多练。教学工具:多媒体。一、 情景导入回顾指数性质:(1)aras=ar+s(a>0,r,s∈Q).(2)(ar)s= (a>0,r,s∈Q).(3)(ab)r= (a>0,b>0,r∈Q).那么对数有哪些性质?如 要求:让学生自由发言,教师不做判断。而是引导学生进一步观察.研探.
对数与指数是相通的,本节在已经学习指数的基础上通过实例总结归纳对数的概念,通过对数的性质和恒等式解决一些与对数有关的问题.课程目标1、理解对数的概念以及对数的基本性质;2、掌握对数式与指数式的相互转化;数学学科素养1.数学抽象:对数的概念;2.逻辑推理:推导对数性质;3.数学运算:用对数的基本性质与对数恒等式求值;4.数学建模:通过与指数式的比较,引出对数定义与性质.重点:对数式与指数式的互化以及对数性质;难点:推导对数性质.教学方法:以学生为主体,采用诱思探究式教学,精讲多练。教学工具:多媒体。一、 情景导入已知中国的人口数y和年头x满足关系 中,若知年头数则能算出相应的人口总数。反之,如果问“哪一年的人口数可达到18亿,20亿,30亿......”,该如何解决?要求:让学生自由发言,教师不做判断。而是引导学生进一步观察.研探.
例7 用描述法表示抛物线y=x2+1上的点构成的集合.【答案】见解析 【解析】 抛物线y=x2+1上的点构成的集合可表示为:{(x,y)|y=x2+1}.变式1.[变条件,变设问]本题中点的集合若改为“{x|y=x2+1}”,则集合中的元素是什么?【答案】见解析 【解析】集合{x|y=x2+1}的代表元素是x,且x∈R,所以{x|y=x2+1}中的元素是全体实数.变式2.[变条件,变设问]本题中点的集合若改为“{y|y=x2+1}”,则集合中的元素是什么?【答案】见解析 【解析】集合{ y| y=x2+1}的代表元素是y,满足条件y=x2+1的y的取值范围是y≥1,所以{ y| y=x2+1}={ y| y≥1},所以集合中的元素是大于等于1的全体实数.解题技巧(认识集合含义的2个步骤)一看代表元素,是数集还是点集,二看元素满足什么条件即有什么公共特性。
函数在高中数学中占有很重要的比重,因而作为函数的第一节内容,主要从三个实例出发,引出函数的概念.从而就函数概念的分析判断函数,求定义域和函数值,再结合三要素判断函数相等.课程目标1.理解函数的定义、函数的定义域、值域及对应法则。2.掌握判定函数和函数相等的方法。3.学会求函数的定义域与函数值。数学学科素养1.数学抽象:通过教材中四个实例总结函数定义;2.逻辑推理:相等函数的判断;3.数学运算:求函数定义域和求函数值;4.数据分析:运用分离常数法和换元法求值域;5.数学建模:通过从实际问题中抽象概括出函数概念的活动,培养学生从“特殊到一般”的分析问题的能力,提高学生的抽象概括能力。重点:函数的概念,函数的三要素。难点:函数概念及符号y=f(x)的理解。
人教版新课标教材必修一的“表达交流”部分,有一个专题是“人性的光辉——写人要凸显个性”。其中的“写法借鉴”部分列举了两则人物描写实例,并归纳出人物描写的几个要点。其训练的思路和方法是很明显的,但所列举的人物描写的实例却不够典型。而必修一第三单元正好是学习写人记事散文,其中的两篇自读课文《记梁任公先生的一次演讲》《金岳霖先生》又是写人记事非常典型的文章,故而我尝试将这两篇文章作为实例和。写人要凸显个性。写作指导结合起来教学。这样设计还有一个目的,那就是解决课程改革中教学内容多而课时紧张的矛盾,提高课堂教学效率。师:今天,我们一起来学习“写人要凸显个性”。这两堂课分四个步骤来完成:一、先学习教材中关于写人方法的介绍,约15分钟;二、快速阅读第三单元的《记梁任公先生的一次演讲》和《金岳霖先生》两篇文章,具体感受其写人的方法,约30分钟;
师:在科学发展过程中,前一个理论体系的不完善之处,往往是新的研究和新的发现的突破口。开普勒之后,意大利天文学家伽利略创制了天文望远镜,用更加精确的观察继续发展和验证哥白尼创立的新天文学理论。除了用望远镜进行天文观察以外,伽利略还开始进行自然科学的实验研究,哪位同学能给大家讲一讲伽利略在比萨斜塔上所作的关于物体自由下落的实验?生:(讲述这一实验)师:所以,伽利略在科学方面更加重要的贡献是奠定了近代实验科学的基础。(2)实验科学和唯物主义师:伽利略从实践上开辟了实验科学的方法,而英国唯物主义哲学家培根则从理论上阐述了实验科学的方法——归纳法。培根和伽利略同被称为实验科学之父,培根还有一句影响深刻的名言:“知识就是力量”,表明了他注重知识,尊崇科学的精神。我们再来概括一下意大利哲学家布鲁诺的唯物主义思想,是否有同学可以简述布鲁诺的生平事迹?
4.That was an experience that frightened everyone. →That was _____________________. 答案:1. taking 2. being discussed 3. in the reading room 4. a frightening experienceStep 6 The meaning and function of V-ing as the predicative动词-ing形式作表语,它通常位于系动词后面,用以说明主语“是什么”或“怎么样”一种表示主语的特质、特征和状态, 其作用相当于形容词; 另一种具体说明主语的内容, 即主语等同于表语, 两者可互换。The music they are playing sounds so exciting. 他们演奏的音乐听起来令人激动。The result is disappointing. 结果令人失望。Our job is playing all kinds of music. 我们的工作就是演奏各种音乐。Seeing is believing. 眼见为实。Step 7 Practice1. It is ________(amaze) that the boy is able to solve the problem so quickly.2. Buying a car is simply _______(waste) money. 3. Please stop making the noise—it’s getting ________(annoy). 4. complete the passage with the appropriate -ing form.La Tomatina is a festival that takes place in the Spanish town Bunol every August. I think many food festivals are __________ because people are just eating. however, this festival is _________ because people don't actually eat the tomatoes. Instead, they throw them at each other! the number of people ________ part in this tomato fight, can reach up to 20,000, and it is a very __________ fight that lasts for a whole hour. The _______ thing is how clean Bunol is after the tomatoes are washed away after the fight. this is because the juice form tomatoes is really good for making surfaces clean!答案:1. amazing 2. wasting 3. annoying4. boring interesting taking exciting amazing
The topic of this part is “Discover the reasons for festivals and celebrations.The Listening & Speaking & Talking part aims at talking about the experiences and feelings or emotions about the festivals and celebrations. This section aims at detecting the reason why the people celebrate the festivals, the time, the places, the types and the way of celebrations. It also explains why some traditions in the old celebrations are disappearing, like the firecrackers in the big cities and some new things are appearing like the prosperity of business or commerce. 1. Students can talk about what festivals they know and the reasons and the way of celebrating them.2. Students should learn the reading skills such as the headline and get the topic sentences, the structures of articles.3. Students can understand the past, the present situation of some festival around the world and why there are some changes about them. 4. Students can have the international awareness about the festivals.1. Students should learn the reading skills such as the headline and get the topic sentences, the structures of articles.2. Students can understand the past, the present situation of some festival around the world and why there are some changes about them.Step 1 Lead in---Small talkWhat festival do you like best ? Why ?I like the Spring Festivals because I can set off the fireworks, receive the lucky money and enjoy the Gala with my families.Step 2 Before reading---Pair workWhy do people celebrate different festivals ?The Spring Festivals is to celebrate the end of winter and the coming of spring and new life.The Mid-autumn Day is to celebrate the harvest and admire the moon.
The theme of this section is “Talk about festival activities and festival experiences”.Festival and holiday is a relaxing and interesting topic for students. This part talks about the topic from the daily life of students’. In the part A ---Listening and Speaking, there are three conversations among different speakers from three countries(Japan, Rio and China), where the speakers are participating in or going to participate in the festivals and celebrations. So listening for the relationship among them is a fundamental task. Actually, with the globalization and more international communication, it is normal for Chinese or foreigners to witness different festivals and celebrations in or out of China. In the Conversation 1, a foreign reporter is interviewing a Japanese young girl who just had participated in the ceremony of the Coming-of-Age Day on the street and asking her feeling about the ceremony and the afterwards activities. Conversation 2, Chinese girl Li Mei is witnessing the Rio Carnival for the first time, and her friend Carla gives her some advice on the costumes which enables her to match with the carnival to have a good time. Conversation 3, a Chinese guide is showing a group of foreign visitors around the Lantern Festival and introducing the customs of the festival to them. The three conversations have a strong vitality and insert the festival and cultural elements from different countries. So perceiving the festivals and cultures from different countries is the second task. At the same time, the scripts also insert the targeted grammar --- v-ing as attributive and predicative, which students can perceive and experience in a real context and make a road for the further study. That is the third task. In the Part B--- Listening and Talking, the theme is “Talk about festival experience”, which is the common topic in our daily conversations. During the conversation, Song Lin, a Chinese student, asked Canadian friend Max about how to spend Christmas. In the conversation, Song Lin talked about experience and the feelings during the Chinese Spring Festival, during which there are not only some enjoyable things but some unpleasant things. After the listening, perhaps students find there are some similarities between Christmas and the Chinese Spring Festival as there are some differences in the origins and celebrations. For example, people always visit friends and relatives, decorate their houses, have a big dinner together, chat and give presents to each other.
Step 3 Analyzing article structureActivity 31. Teachers raise questions to guide students to analyze the chapter structure of this diary and think about how to describe the festival experience. (1)What should be included in the opening/body/closing paragraph(s)?(2)How did the writer arrange his/her ideas?(3)What kind of interesting details did the writer describe?(4)How did the writer describe his/her feelings/emotions during the event?2. Students read and compare the three sentence patterns in activity 2. Try to rewrite the first paragraph of the diary with these three sentence patterns. After that, students exchange corrections with their partners. Such as:●This was my first time spending three days experiencing the Naadam Festival in China’s Inner Mongolia Autonomous Region and it was an enjoyable and exciting experience. ●I'll never forget my experience at the Naadam Festival because it was my first time to watch the exciting Mongolian games of horse racing, wrestling, and archery so closely. ●I'll always remember my first experience at the Naadam Festival in China’s Inner Mongolia Autonomous Region because it was so amazing to spend three days witnessing a grand Mongolian ceremony. Step 4 Accumulation of statementsActivity 41. Ask the students to read the diary again. Look for sentences that express feelings and emotions, especially those with the -ing form and the past participle. Such as:● …horse racing, wrestling, and archery, which are all so exciting to watch. ● some amazing performances● I was surprised to see…● I was a little worried about. . . ● feeling really tiredOther emotional statements:●I absolutely enjoyed the archery, too, but the horse races were my favourite part. ●I'm finally back home now, feeling really tired, but celebrating Naadam with my friend was totally worth it. ●He invited me back for the winter to stay in a traditional Mongolian tent and cat hot pot. I can’t wait!2. In addition to the use of the -ing form and the past participle, the teacher should guide the students in the appreciation of these statements, ask them to memorize them, and encourage them to use them reasonably in writing practice.
Example:One day, a poor boy who was trying to pay his way through school by sending newspapers door to door found that he only had one dime(一角)left. He was so hungry that he decided to beg for a meal at the next house.However, he lost his nerve when a lovely young woman opened the door. Instead of a meal he asked for a drink of water. She thought he looked hungry so she brought him a large glass of milk. He drank it slowly, and then asked, “How much do I owe you?” “You don’t owe me anything,” she replied, “Mother has taught me never to accept pay for a kindness.” “Then I thank you from the bottom of my heart.” With these words, Howard Kelly left that house.Years later the woman became badly ill and was finally sent to the hospital in a big city. Dr. Howard Kelly, now famous, was called in. When he heard the name of the town she came from, a strange light filled his eyes. Dressed in his doctor’s clothes, Dr. Kelly went into her room and recognized her at once. From that day on, he gave special attention to her, and decided to do his best to save her life.At last the woman was saved. Dr. Kelly asked the business office to pass the final bill to him. He looked at it and then wrote something on the side. The bill was sent to the woman’s room. She was afraid to open it because she was sure that it would take the rest of her life to pay for it off. Finally she looked, and the note on the side of the bill caught her attention. She read these words: “Paid in full with a glass of milk, Dr. Howard Kelly.” Tear of joy flooded her eyes.
Step 4 PracticeRead the conversation. Find out which words have been left out.Justin: Linlin, I’m going to Guizhou Province next month. I’m super excited! Any recommendations for places to visit?Linlin: Wow, cool! Guizhou is a province with a lot of cultural diversity. Places to visit...well, definitely the Huangguoshu Waterfall first.Justin: What’s special about the waterfall?Linlin: Well, have you ever heard of the Chinese novel Journey to the West ?Justin: Yes, I have. Why ?Linlin: In the back of the waterfall, you will find a cave, which is the home of the Monkey King.Justin: Really? Cool! I’ll definitely check it out.Linlin:And I strongly recommend the ethnic minority villages. You’ll find Chinese culture is much more diverse than you thought.Justin:Sounds great, thanks.Answers:Justin: Linlin, I’m going to Guizhou Province next month. I’m super excited! Do you have any recommendations for places to visit?Linlin: Wow, that’s cool! Guizhou is a province with a lot of cultural diversity. What are some places to visit in Guizhou ? Well, definitely the Huangguoshu Waterfall is the first place to visit in Guizhou Province.Justin: What’s special about the waterfall?Linlin: Well, have you ever heard of the Chinese novel Journey to the West ?Justin: Yes, I have heard of the Chinese novel Journey to the West . Why do you ask if I have heard of the Chinese novel Journey to the West?Linlin: In the back of the waterfall, you will find a cave, which is the home of the Monkey King from Journey to the West.Justin: That’s really true? It’s Cool! I’ll definitely check it out.Linlin:And I strongly recommend the ethnic minority villages on your trip to Guizhou Province. You’ll find Chinese culture is much more diverse than you thought it was.Justin:This all sounds great, thanks.
1. In Picture 1 and Picture 2, where do you think they are from? How do you know?From their wearings, we can know they are from ethnic minority of China--- Miao and Dong.Picture 1, they are playing their traditional instrument lusheng in their traditional costumes.Picture 2. the girls are Miao because they wear their traditional costumes and silver accessory.2. In Picture 3, can you find which village it is? What time is it in the picture?It is Dong village. It is at night. Step 2 While-listeningJustin met a new friend while traveling in Guizhou. Listen to their conversation and complete the summaries below.Part 1Justin and Wu Yue watched some Miao people play the lusheng. The instrument has a history of over 3,000 years and it is even mentioned in the oldest collection of Chinese poetry. Then they watched the lusheng dance. Justin wanted to buy some hand-made silver/traditional accessories as souvenirs. He was told that the price will depend on the percentage of silver. Part 2They will go to a pretty Dong minority village called Zhaoxing. they will see the drum towers and the wind and rain bridges. They may also see a performance of the Grand Song of the Dong people.Step 3 Post-listening---TalkingWork in groups. Imagine Justin is telling some friends about his trip to Guizhou. One of you is Justin and the rest of you are his friends. Ask Justin questions about his trip and experience. The following expressions may help you.
PPT全称是PowerPoint,LFPPT为你提供免费PPT模板下载资源。让你10秒轻松搞定幻灯片制作,打造⾼颜值的丰富演示文稿素材模版合集。