-
新人教版高中英語必修2Unit 3 The Internet-Listening &Speaking＆Talking教案一
Listening and Speaking introduces the topic of “ask about online habits”. Many middle school students have been surfing the Internet for many years, but what they do with the Internet and how much time they spend every day may not be very clear to themselves, nor to other students. This section allows students to investigate their peers' Internet use, which is conducive to their mutual understanding and understanding of the Internet. It can also help them reflect on their own online behavior, learn from other people's good online habits, and get rid of their bad online behavior.The listening text of this section is an investigation interview. The investigators interview specific groups with the same questions to obtain information, so as to understand their views, practices or attitudes on this issue. There are two specific questions: “how much time do you spend online every day? What do you usually do online?”. The answers of the three respondents provide rich and different information, and achieve the purpose of the investigators. The oral discourse structure of survey interviews generally includes greeting and explaining the purpose of the interview, presenting the interview questions and the respondents' answers. Listening and Talking introduces the theme of “choosing the right application ". Listening text is a conversation between Laura and Xiao Bo. In this part of listening, “oink”； “piggy bank” may cause the students' hearing comprehension limitation. Oink refers to sound word and pig's sound. So, add some oink to my piggy bank is often used to describe "making a little money".1. Guide students to understand the content of listening texts in terms of listening for definitions.2. Cultivate students' ability to define words and understand an investigation interview.
新人教版高中英語必修2Unit 3 The Internet-Reading and Thinking教案一
Paragraph 3. Jan decided to start an IT club to teach old people how to use computers and the Internet. Paragraph 4. Jan has started taking online classes to learn more about how to use the Internet to make society better. Paragraph 5. Jan’s life has been greatly improved by the Internet. Step 5: Critical thinking:(1)How do you arrange your time spent on study and the Internet? Is it reasonable? I usually surf the Internet using my mobile phone for only an hour after class, and it is reasonable for me.(2)What are your online activities? Are they safe? I chat with my friends, read news and play games. I never give away my private information so I think they are safe.Step 4: summary Much has been written about the wonders of the World Wide Web. There are countless articles (1)______(tell) us how the Internet has made our lives more convenient. But the Internet has done a lot (2)_____(much) for people than simply make life more convenient. People’s lives (3) _________________(change) by online communities and social networks so far. Take Jan for example, who developed a serious illness that made her (4)_____(stick) at home with only her computer to keep (5)___(she) company. She joined an online group (6)______ she could share problems, support and advice with others. She considered the ability to remove the distance between people as one of the greatest (7)_______(benefit). She was so inspired (8)____ she started an IT club in which many people have been helped. She has started to learn more about how to use the Internet to make society better. Her next goal is to start a charity website to raise money (9)___ children in poor countries. Jan’s life has been (10)______(great) improved by the Internet. Step 5 Homework:Review what we have learned and find out the key language points in the text.
新人教版高中英語必修2Unit 4 History and Traditions-Listening＆Speaking＆Talking教案一
This unit is about history and traditions. From the opening page, we can know that this unit will introduce the history and traditions around the world. As Marcus Garvey says “A people without the knowledge of their past history, origin and culture is like a tree without roots”, it is important for students to realize the importance and value of knowing the history and traditions and their further meanings. And this part ( listening and speaking ) is divided into two parts: Part A---share views on historic sites, Part B ---talk about a visit to a historic tourist destination. By talking with a foreigner, the speakers introduce the historic attractions and their cultures. Part A is that William, a British student, who was going to visit the Confucius Temple and a Chinese student, Xiao Kong, who was going to the Confucius Temple to meet with the members of the research group, went together and exchanged their views on the Confucius Temple, Confucius, Confucius' descendants and Confucius' educational thoughts. Part B is a conversation between Xiao Yan, a youth hostel receptionist and Paul, a backpacker about the feelings and experience after visiting the Chinese famous tourist attraction Pingyao.1. Guide students to understand the content of listening texts in terms of the whole and key details; 2. Cultivate students' ability to guess the meaning of words in listening; discuss with their peers how to talk about historic spots and great person.3. Instruct students to use functional sentences of showing one’s excitement, surprise and disappointment.1. Guide students to understand the content of listening texts in terms of the whole and key details; 2. Cultivate students' ability to discuss with their peers the related topics.3. Enable students to use the functional items of showing one’s excitement, surprise and disappointment.
新人教版高中英語必修2Unit 4 History and Traditions-Reading and Thinking教案一
Features of languages1．Finally, in the 20th century, the southern part of Ireland broke away from the UK, which resulted in the full name we have today: the United Kingdom of Great Britain and Northern Ireland．該句是一個復合句。該句主句為：the southern part of Ireland broke away from the UK；which resulted in the full name we have today為which引導的定語從句代指前面整句話的內容，we have today為定語從句修飾先行詞name。譯文：最后，在20世紀，愛爾蘭南部脫離英國，這導致了我們今天有的英國的全名：大不列顛及北愛爾蘭聯(lián)合王國。2．Almost everywhere you go in the UK, you will be surrounded by evidence of four different groups of people who took over at different times throughout history．該句是一個復合句。該句主句為：you will be surrounded by evidence of four different groups of people；其中Almost everywhere you go in the UK為讓步狀語從句； who took over at different times throughout history為定語從句修飾先行詞people。譯文：幾乎無論你走到英國的任何地方，你都會發(fā)現歷史上有四種不同的人在不同的時期統(tǒng)治過英國。3．The capital city London is a great place to start, as it is an ancient port city that has a history dating all the way back to Roman times．該句是一個復合句。該句主句為：The capital city London is a great place to start; as it is an ancient port city that has a history dating all the way back to Roman times．為原因狀語從句；dating all the way back to Roman times為現在分詞短語作定語修飾history。
新人教版高中英語必修2Unit 5 Music-Discovering Useful Structures教案一
Step1:自主探究。1．(教材P52)Born(bear) in the USA on 2 January 1970, Whitacre began studying music at the University of Nevada in 1988．2．(教材P52) Moved(move) by this music, he said, “It was like seeing color for the first time．”3．(教材P56)I was very afraid and I felt so alone and discouraged(discourage)．4．(教材P58)Encouraged(encourage) by this first performance and the positive reaction of the audience, I have continued to play the piano and enjoy it more every day．Step2:語法要點精析。用法1：過去分詞作表語1）．過去分詞可放在連系動詞be, get, feel, remain, seem, look, become等之后作表語，表示主語所處的狀態(tài)Tom was astonished to see a snake moving across the floor．湯姆很驚訝地看到一條蛇正爬過地板。Finally the baby felt tired of playing with those toys．終于嬰兒厭倦了玩那些玩具。注意：1）.過去分詞作表語時與被動語態(tài)的區(qū)別過去分詞作表語時，強調主語所處的狀態(tài)；而動詞的被動語態(tài)表示主語是動作的承受者，強調動作。The library is now closed．(狀態(tài))圖書館現在關閉了。The cup was broken by my little sister yesterday．(動作)昨天我妹妹把杯子打碎了。2）感覺類及物動詞的現在分詞與過去分詞作表語的區(qū)別過去分詞作表語多表示人自身的感受或事物自身的狀態(tài)，常譯作“感到……的”；現在分詞多表示事物具有的特性，常譯作“令人……的”。
新人教版高中英語必修2Unit 5 Music-Reading and Thinking教案一
This section focuses on "learning about experiencing music Online". This virtual choir is a new form of music performance. Members from all over the world don't need to love to come to a place. Instead, they use the new technology to model the various parts and wonderful virtual harmony group of music in the family. Students need to understand the main meaning of each paragraph. Finding topic sentences is an important way to understand the general idea of a paragraph. After the topic sentence, it is usually the detail sentence that supports and explains the topic sentence. Some paragraphs have obvious subject sentences, for example, the first sentence of the second paragraph is the subject sentence of the paragraph, and the following sentenceStudents need to pay attention to the topic sentences and key sentences, and then pay attention to how the sentences after the meaning explain, explain and support the topic sentences or key sentences before.1.Guide students to learn about experiencing music online2.Guide students to scan and circle the information in the text.3.Guide students to find the numbers and dates to fill in the timeline.4.Guide students to learn more about music by completing the sentences with the correct forms of the words and phrases. And then make a mind map about the outline of the passage.1. Guide students to pay attention to reading strategies, such as prediction, self-questioning and scanning.2. Help students sort out the main meaning of each paragraph and understand the narrative characteristics of "timeline” in illustrative style.3. Lead students to understand the changes that have been caused by the Internet.
新人教版高中英語必修2Unit 5 Music-Reading For Writing教案一
(4)Now we have heard a number of outstanding speeches ... 我們已經聆聽了許多精彩的發(fā)言……(5)Because we wanted the nations of the world, working together, to deal with ... 因為我們希望全世界各國團結起來去應對……(6)And if we do not act ... 如果我們不采取行動……(7)Now, I share the concerns that have been expressed ... 我也同意對于……表達的擔心(8)Let us show the world that by working together we can ... 讓我們告訴全世界，通過一起努力我們可以……(9)It is now time for us to ... 是時候我們……(10)And I have always wished that ... 我一直希望……(11)Thank you for letting me share this day with me.感謝你們和我共度這一天。實踐演練：假如你是高中生李華，你校將舉辦一次以“音樂”為主題的演講比賽，請你按照主題，寫下你的演講稿。注意：詞數100左右。First of all, thank you for listening to my speech. My topic is: love music like love yourself.Music is like the air we need to maintain our normal lives around us. You can't imagine how terrible a world without music would be. Movies and TV shows have no music, only dry conversations and scenes; mobile phones only vibrations; streets only noisy crowds; cafes, western restaurants only depressed meals. What a terrible world it is!As a student, I hope we all can enjoy the fun brought by music in our spare time. Instead of just listening to music, we can even make our own music. Let's enjoy the fun of music!Thanks again for your attention!
新人教版高中英語必修2Unit 2 Wildlife Protection-Discovering Useful Structure教案一
The activity topic of this section is "report an ongoing event", and the structure is the passive voice of present continuous tense. Rare wild animals are suffering from large-scale poaching, and species are on the brink of danger. Rescue operations are underway. "Being" and "suffering" are the meanings of the present progressive passive voice.The usage of present progressive passive voice is of great importance in writing a good discourse and appreciating some difficult language items, so it is vital to master it and use it flexibly in a context.1. Motivate Ss to deepen the understanding of the usage of present progressive passive voice in a fixed context.2. Enable Ss to master the usage of present progressive passive voice and use it flexibly in a context.3. Lead Ss to construct sentences or appreciate sentences used master it and use it flexibly in a context.1. Help students to appreciate the function of the usage of present progressive passive voice in a sentence2. Instruct students to write essays using the proper usage of present progressive passive voice.Look at the picture and tell me what are workers doing? What is the house being done?
新人教版高中英語必修2Unit 2 Wildlife Protection-Reading and Thinking教案一
The listening and speaking part aims at how to protect and help endangered animals by listening, speaking and talking about the facts and reasons. This lesson analyzes the decreasing clause of Tibetan antelope population and the measures of protecting Tibetan antelopes. So students can be guided to learn to analyse the title and use different reading skills or strategies, like scanning, skimming and careful reading.1. Read quickly to get the main ideas and the purpose of going to Tibetan; read carefully to understand what the author see and think.2. Understand the sentences of the present continuous passive voice such as “Much is being done to protect wildlife.” and the inverted sentence “Only when we learn to exist in harmony with nature can we stop being a threat to wildlife and to our planet.”3. Enhance the awareness of protecting wildlife.4. Cultivate the reading methods according to different materials.1. Read quickly to get the main ideas and the purpose of going to Tibetan; read carefully to understand what the author see and think.2. Understand the sentences of the present continuous passive voice such as “Much is being done to protect wildlife.” and the inverted sentence “Only when we learn to exist in harmony with nature can we stop being a threat to wildlife and to our planet.”3. Cultivate the reading methods according to different materials.Step 1 Leading-inWatch a video about elephants and whales and then ask:Why are they endangered ? They are killed/hunted
新人教版高中英語必修2Unit 3 The Internet-Discovering Useful Structure教案一
This unit is about the Internet, which has a great influence to our humans and our lives. During the Listening & Speaking & Talking and Reading and Thinking section, the influence in examples has been shown. Thus, use the Present Perfect Tense is appropriate. However, in order to show the justice or weaken the doer of the behavior/action, it’s better to use the Present Perfect Passive Voice than the Present Perfect Tense. Besides, having learned to use the Present Perfect Passive Voice, students can beautify their language in their writing. 1. Learn the structure of the Present Perfect Passive Voice and its functions. 2. Learn to change the sentences with the Present Perfect Passive Voice into the sentences with the Present Perfect Passive Voice. 3. Learn to write sentences with the Present Perfect Passive Voice flexibly according to the context. 1. Learn the structure of the Present Perfect Passive Voice and its functions. 2. Learn to change the sentences with the Present Perfect Passive Voice into the sentences with the Present Perfect Passive Voice. 3. Learn to write sentences with the Present Perfect Passive Voice flexibly according to the context. Step 1 Observe the following sentences, then change the sentences into passive voice.He has been selected to take part in the sports meeting．(肯定句)他已被挑選出來參加運動會。The ink has not been removed from his overcoat．(否定句)墨跡還沒有從他外套上去掉。
新人教版高中英語必修2Unit 4 History and Traditions-Discovering Useful Structure教案一
Step 5 Practice一、完成下列句子。1. Judy and I _______________（把車停下來(park)）in an underground car Park near Trafalgar Square, where we could ______________________(讓我們的車充電（charge)).2. When we finally reached the service desk to ask for audio guides, we heard it ___________ that there were no audio guides____________(留下，剩下）.3. We__________________________（發(fā)現自己對...很驚訝）the large number of visitors and the amount of noise at the entrance of the National Gallery.4. Judy ____________________(眼神專注于） Van Gogh’s Sunflowers. It was hard to approach the painting as there were so many people around.5. She ____________________(把這幅畫的復制品裝箱（box)） to ensure that it was delivered safely.答案：1.had our car parked get our car battery charged 2. announced left 3. found ourselves very surprised 4. had her eyes fixed on 5. had a copy of the painting boxed二、用過去分詞對下列句子進行改寫。1. Loch Ness was surrounded by beautiful natural landscape, which made it look amazing.2. Carl and his friend stayed with a generous family who offered them bread with butter and honey that was homemade.3. The family’s ancestors once attended to soldiers who were wounded in the First World War.4. The young people were attracted by the legend of Loch Ness. They watched over the lake with their cameras and binoculars, which were positioned on the hill.答案：1. Loch Ness surrounded by beautiful natural landscape looks amazing.2. Carl and his friends stayed with a generous family who offered them homemade bread with butter and honey.3. The family’s ancestors once attended to wounded soldiers in the First World War.4. The young people attracted by the legend of Loch Ness watched over the lake with their cameras and binoculars positioned on the hill.
新人教版高中英語必修2Unit 3 The Internet-Reading For Writing教案一
⑦identity theft 身份盜竊⑧chat room 聊天室⑨draft your blog post 起草博客帖子⑩post embarrassing photos 張貼尷尬照片 【話題句式】 1. How do you stay safe online and avoid bad experiences on the Internet? 你如何在網上保持安全, 避免在網上的不良經歷? 2. I’m not an expert, but many years as a blogger have taught me a thing or two. 我不是專家, 但作為一個博主, 我已經學了好幾年了。 3. If you see or read something that makes you feel uncomfortable, leave the site immediately. 如果你看到或讀到一些讓你覺得不舒服的東西, 立即離開這個網站。4. Don’t give out your address or phone number. 別告訴別人你的地址或電話號碼。 5. Identity theft is a common and serious problem. 身份盜竊是一個常見而嚴重的問題。6. Being online is no excuse for being rude, and you don’t want to become a target for a troll or cyberbully. 上網并不是無禮的借口, 你也不想成為發(fā)挑釁帖子的人或網絡惡霸的目標。 7. Trolls often use several false names so that they can stay on a site. 發(fā)挑釁帖子的人經常使用幾個假名, 這樣他們就可以留在一個網站上。8. However, the more polite you are, the less likely it is you will be attacked. 然而, 你越有禮貌, 你被攻擊的可能性就越小。
新人教版高中英語必修3Unit 2 Morals and virtues教學設計一
(2) students are divided into groups according to the requirements of activity 3. Each student shares a story of personal experience or hearing-witnessing kindness, and then selects the most touching story in the group and shares it with the whole class. Before the students share the story, the teacher can instruct them to use the words and sentence patterns in the box to express. For example, the words in the box can be classified:Time order: first of all, then, after that, later, finally logical relationship :so, however, although, butTeachers can also appropriately add some transitional language to enrich students' expression:Afterwards, afterwards, at last, in the end, eventuallySpatial order: next to, far from, on the left, in front ofOtherwise, nevertheless, as a result, therefore, furthermore, in addition, as well asSummary: in a word, in short, on the whole, to sum up, in briefStep 8 Homework1. Understand the definition of "moral dilemma" and establish a correct moral view;2. Accumulate vocabulary about attitudes and emotions in listening texts and use them to express your own views;3. Complete relevant exercises in the guide plan.1、通過本節(jié)內容學習，學生能否理解理解“道德困境”的定義；2、通過本節(jié)內容學習，學生能否通過說話人所表達的內容、說話的語氣、語調等來判斷其態(tài)度和情緒；3、通過本節(jié)內容學習，學生能否針對具體的道德困境發(fā)表自己的看法和見解，能否掌握聽力理訓練中的聽力策略。
新人教版高中英語必修3Unit 3 Diverse Cultures教學設計一
Activity 81.Grasp the main idea of the listening.Listen to the tape and answer the following questions:Who are the two speakers in the listening? What is their relationship?What is the main idea of the first part of the listening? How about the second part?2.Complete the passage.Ask the students to quickly review the summaries of the two listening materials in activity 2. Then play the recording for the second time.Ask them to complete the passage and fill in the blanks.3.Play the recording again and ask the students to use the structure diagram to comb the information structure in the listening.(While listening, take notes. Capture key information quickly and accurately.)Step 8 Talking Activity 91.Focus on the listening text.Listen to the students and listen to the tape. Let them understand the attitudes of Wu Yue and Justin in the conversation.How does Wu Yue feel about Chinese minority cultures?What does Justin think of the Miao and Dong cultures?How do you know that?2.learn functional items that express concerns.Ask students to focus on the expressions listed in activity. 3.And try to analyze the meaning they convey, including praise (Super!).Agree (Exactly!)"(You're kidding.!)Tell me more about it. Tell me more about it.For example, "Yeah Sure." "Definitely!" "Certainly!" "No kidding!" "No wonder!" and so on.4.Ask the students to have conversations in small groups, acting as Jsim and his friends.Justin shares his travels in Guizhou with friends and his thoughts;Justin's friends should give appropriate feedback, express their interest in relevant information, and ask for information when necessary.In order to enrich the dialogue, teachers can expand and supplement the introduction of Miao, dong, Lusheng and Dong Dage.After the group practice, the teacher can choose several groups of students to show, and let the rest of the students listen carefully, after listening to the best performance of the group, and give at least two reasons.
關于六月份世界環(huán)境日小學國旗下講話稿6月5日關于保護環(huán)境
各位老師，各位同學：早上好！6月5日是世界環(huán)境日，所以，今天我們?yōu)榇蠹規(guī)淼氖且皇自姼琛督o未來一片綠色》輕輕地打開地球畫冊山山水水都在問我；二十一世紀的孩子們，你想給未來的地球留下什么？是留下一棵樹，還是留下一朵花？是留下一個生命的春天，還是留下一片永恒的綠洲？啊，我們鏗鏘做答：給未來留下一個更美的地球，和一首綠色、和平的贊歌！深情地揮動七彩畫筆，自然天地云涌浪起；二十一世紀的孩子們，
優(yōu)化營商環(huán)境服務中心民營經濟服務工作總結（街道）
一、堅持疫情防控常態(tài)化，全面支持企業(yè)復工復產新年伊始，**街道春潮涌動，各行各業(yè)相繼開工趕生產，為實現首季“開門紅”，**街道堅持疫情防控常態(tài)化，以重點項目建設、重點企業(yè)服務為抓手，提前謀劃、集中發(fā)力、強化措施，瞄準全年目標任務，狠抓全年經濟工作，支持企業(yè)員工留崗，全力助推轄區(qū)企業(yè)復工復產，保障轄區(qū)經濟發(fā)展穩(wěn)中推進。今年以來，街道與企業(yè)、項目單位積極對接，在積極做好疫情防控工作的同時，鼓勵企業(yè)抓緊全面復工復產。為支持疫情期間經濟發(fā)展，鼓勵及早復工，依據《關于下達**市規(guī)上服務業(yè)企業(yè)外省員工新春留崗獎勵資金的通知》（筑發(fā)改三產〔****〕***號）、《**市財政局**市商務局關于下達**市****年限額以上批零餐企業(yè)外省員工新春留崗獎勵資金的通知》（筑財建〔****〕**號）文件要求，街道積極組織轄區(qū)企業(yè)開展扶持獎勵申報，以高效、便捷、規(guī)范為原則，采取實地走訪、電話走訪等多種形式全力做好春節(jié)期間企業(yè)外省員工留崗獎勵的宣傳和申報工作，期間共宣傳通知企業(yè)***余家，搜集符合條件的申報企業(yè)資料**家，合計申報人數***人，實際審批通過人數***人，發(fā)放兌現新春留崗獎勵合計**萬元。
雙曲線的簡單幾何性質（1）教學設計人教A版高中數學選擇性必修第一冊
問題導學類比橢圓幾何性質的研究，你認為應該研究雙曲線x^2/a^2 -y^2/b^2 =1 (a>0，b>0)，的哪些幾何性質，如何研究這些性質1、范圍利用雙曲線的方程求出它的范圍，由方程x^2/a^2 -y^2/b^2 =1可得x^2/a^2 =1+y^2/b^2 ≥1 于是，雙曲線上點的坐標（ x ， y ）都適合不等式，x^2/a^2 ≥1，y∈R所以x≥a 或x≤-a; y∈R2、對稱性 x^2/a^2 -y^2/b^2 =1 (a>0，b>0)，關于x軸、y軸和原點都是對稱。x軸、y軸是雙曲線的對稱軸，原點是對稱中心，又叫做雙曲線的中心。3、頂點（1）雙曲線與對稱軸的交點，叫做雙曲線的頂點 .頂點是A_1 （-a,0）、A_2 （a,0），只有兩個。（2）如圖，線段A_1 A_2 叫做雙曲線的實軸，它的長為2a,a叫做實半軸長；線段B_1 B_2 叫做雙曲線的虛軸，它的長為2b,b叫做雙曲線的虛半軸長。（3）實軸與虛軸等長的雙曲線叫等軸雙曲線4、漸近線（1）雙曲線x^2/a^2 -y^2/b^2 =1 (a>0，b>0)，的漸近線方程為：y=±b/a x（2）利用漸近線可以較準確的畫出雙曲線的草圖
拋物線的簡單幾何性質（1）教學設計人教A版高中數學選擇性必修第一冊
問題導學類比用方程研究橢圓雙曲線幾何性質的過程與方法，y2 = 2px (p＞0)你認為應研究拋物線的哪些幾何性質，如何研究這些性質？1. 范圍拋物線 y2 = 2px (p＞0) 在 y 軸的右側，開口向右，這條拋物線上的任意一點M 的坐標 (x, y) 的橫坐標滿足不等式 x ≥ 0；當x 的值增大時，|y| 也增大，這說明拋物線向右上方和右下方無限延伸．拋物線是無界曲線．2. 對稱性觀察圖象，不難發(fā)現，拋物線 y2 = 2px (p＞0)關于 x 軸對稱，我們把拋物線的對稱軸叫做拋物線的軸．拋物線只有一條對稱軸． 3. 頂點拋物線和它軸的交點叫做拋物線的頂點.拋物線的頂點坐標是坐標原點 (0, 0) ．4. 離心率拋物線上的點M 到焦點的距離和它到準線的距離的比，叫做拋物線的離心率. 用 e 表示，e = 1．探究如果拋物線的標準方程是〖 y〗^2=-2px(p>0), ②〖 x〗^2=2py(p>0), ③〖 x〗^2=-2py(p>0), ④
橢圓的簡單幾何性質（1）教學設計人教A版高中數學選擇性必修第一冊
1.判斷 (1)橢圓x^2/a^2 +y^2/b^2 =1(a>b>0)的長軸長是a. ( )(2)若橢圓的對稱軸為坐標軸,長軸長與短軸長分別為10,8,則橢圓的方程為x^2/25+y^2/16=1. ( )(3)設F為橢圓x^2/a^2 +y^2/b^2 =1(a>b>0)的一個焦點,M為其上任一點,則|MF|的最大值為a+c(c為橢圓的半焦距). ( )答案:(1)× (2)× (3)√ 2.已知橢圓C:x^2/a^2 +y^2/4=1的一個焦點為(2,0),則C的離心率為( )A.1/3 B.1/2 C.√2/2 D.(2√2)/3解析:∵a2=4+22=8,∴a=2√2.∴e=c/a=2/(2√2)=√2/2.故選C.答案:C 三、典例解析例1已知橢圓C1:x^2/100+y^2/64=1,設橢圓C2與橢圓C1的長軸長、短軸長分別相等,且橢圓C2的焦點在y軸上.(1)求橢圓C1的半長軸長、半短軸長、焦點坐標及離心率;(2)寫出橢圓C2的方程,并研究其性質.解:(1)由橢圓C1:x^2/100+y^2/64=1,可得其半長軸長為10,半短軸長為8,焦點坐標為(6,0),(-6,0),離心率e=3/5.(2)橢圓C2:y^2/100+x^2/64=1.性質如下:①范圍:-8≤x≤8且-10≤y≤10;②對稱性:關于x軸、y軸、原點對稱;③頂點:長軸端點(0,10),(0,-10),短軸端點(-8,0),(8,0);④焦點:(0,6),(0,-6);⑤離心率:e=3/5.
用空間向量研究直線、平面的位置關系（1）教學設計人教A版高中數學選擇性必修第一冊
二、探究新知一、空間中點、直線和平面的向量表示1.點的位置向量在空間中,我們取一定點O作為基點,那么空間中任意一點P就可以用向量(OP) ?來表示.我們把向量(OP) ?稱為點P的位置向量.如圖.2.空間直線的向量表示式如圖①,a是直線l的方向向量,在直線l上取(AB) ?=a,設P是直線l上的任意一點,則點P在直線l上的充要條件是存在實數t,使得(AP) ?=ta,即(AP) ?=t(AB) ?.如圖②,取定空間中的任意一點O,可以得到點P在直線l上的充要條件是存在實數t,使(OP) ?=(OA) ?+ta, ①或(OP) ?=(OA) ?+t(AB) ?. ②①式和②式都稱為空間直線的向量表示式.由此可知,空間任意直線由直線上一點及直線的方向向量唯一確定.1.下列說法中正確的是( )A.直線的方向向量是唯一的B.與一個平面的法向量共線的非零向量都是該平面的法向量C.直線的方向向量有兩個D.平面的法向量是唯一的答案:B 解析:由平面法向量的定義可知,B項正確.
