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(diào)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(diào)動作。The library is now closed.(狀態(tài))圖書館現(xiàn)在關(guān)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(xiàn)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(xiàn)在分詞多表示事物具有的特性,常譯作“令人……的”。
1. Get basic information about Eric; read deeply to understand the history and development of the virtual choir.2. Understand what the function of the virtual choir is and how to make a virtual choir.3. Understand the meaning of some languages in the context of the text through question guidance, such as “Many people do not have close friends or contacts who have the same interest in music.” and so on.Step 1 Leading-in1. Answer the following questions.Q1:Do you know the Apps like Tik Tok and Quick Hand?Q2: Do you want to make a Tik Tok video or a Quick Hand video?2. Play a Tik Tok video Step 2: Understanding the title Q1:What does the title mean ?Q2: Is the article a narration or exposition? Why? Q3: Can you change the title ? If you can, what is the title?Step 3: Scanning the whole text and getting the basic information1. Answer the following questions.Q1:Who came up with the idea for a virtual choir?Q2: Where did Eric studied the musical composition?Q3: What is his song?2. Find the main idea of each paragraph3. Deal with some new words.Step 4: Reading carefully to get detailed informationPara 1 How to make a virtual choir1. PreparationA. tools: a virtual camera; an Internet connectionB. hero/heroin: friends or some individuals who have the same interests2. Process
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.
(4)Now we have heard a number of outstanding speeches ... 我們已經(jīng)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(jié)起來去應(yīng)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(dān)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(shù)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!
2. Explore the significance of the establishment of Sarek National Park.Q1: Which event is the most important one in the park’s history?Ss: The establishment of Sarek national park in 1909 is the most important one.Q2: Is it worth making a place like Sarek a national park? Give your reasons.Ss: Yes. In this way, the place can be kept in its natural state and natural beauties and other rare and valuable resources can be preserved instead of being destroyed by endless exploitation driven by profits.Q3: How does the writer organize his introduction to the history of Sarek?Ss: The writer organizes his introduction in the sequence of time, using time indicators such as “used to”, “around 9,000 years ago”, “soon after”, “following the reindeer”, and “in 1909”.Q4: What is the feature of the language used to introduce the history of the park?Ss: The introduction to the park is to provide facts, using time indicators to organize the events. Sentences starts with “third person” and passive voice is used more often, feeling objective.【設(shè)計意圖】學(xué)生尋找和梳理公園歷史上的重要事件,體會人與自然的和諧關(guān)系,評鑒介紹性語言的特點。【核心素養(yǎng)提升點】發(fā)展自主提取、梳理文本信息能力,訓(xùn)練邏輯思維和高階思維。Activity 3: Highlighting the secret of the text
【設(shè)計意圖】以“新科技是一把雙刃劍”為主題開展討論活動。這個話題比較大,所以給了一定的限制,首先需要以智能家居為例來闡述科技發(fā)展對未來生活產(chǎn)生的影響,然后列舉其優(yōu)點和缺點,最后就以上現(xiàn)象發(fā)表自己的觀點。這個活動是對整個文本的創(chuàng)意性總結(jié)與意義的升華,留給學(xué)生一定的想象空間,學(xué)生借此機會可以運用文本內(nèi)容和語言表達自己對科技發(fā)展的看法和態(tài)度。Assignments:1. Finish Exercise 4 on Page 15 of the textbook.A smart home is one that integrated computers into the structure of the building itself. In this way, many of the things that we now do ourselves become automatic. For example, the smart home could control the air conditioning and lights so that you would no longer have to turn switches on and off, and so that your home would be more energy-efficient. The smart home could also monitor itself to make sure that everything is working as it should, and send you warnings if there is a problem. Such smart homes could even be programmed to detect your health problems, and then give you reasonable advice as to the food you should eat or if you should see a doctor. So, in a sense, smart homes will lead us to living smarter lives.2.Create a smart function for your home, and share your creation in the next period.
本閱讀材料的話題是交際中的肢體語言,作者從三個方面講述了肢體語言的特征與作用,通過主題句和舉例闡述的方式讓讀者了解不同文化中肢體語言的相同或者不同的意義,并從更抽象、概括的維度深入認識肢體語言的特點,理解肢體語言的作用?;谥w語言的特點,作者提醒讀者在與人交流中,尤其是當(dāng)文化背景有差異的時候,要使用得體的肢體語言,尊重、理解和包容不同的文化,進行有效、有素養(yǎng)的溝通。文本共由六個段落組成,篇章結(jié)構(gòu)為“總—分”。第一段用簡練的語言引出了話題,并且從我們自身表達的需要和了解他人感受兩個角度講述了肢體語言的作用。第二段闡述了肢體語言的第一個重要特點——肢體語言在不同的文化中有不同的內(nèi)涵——這也是文中寫作篇幅最大的一個要點,最為重要。通過講述肢體語言的這一特點,作者向讀者傳遞了要尊重不同的文化、要使用與所在文化相宜的肢體語言。
[2] An important breakthrough…was… [3] Another innovation was … [4] the emphasis increasingly shifted from…to… [5] New ideas and values gradually replaced… [6] While his paintings still had religious themes… … T: All these expressions serve to show how Western painting has developed. Some of them share similar structure but with varied use of words, which makes the text vivid and more readable. 【設(shè)計意圖】主題類語言整理有助于學(xué)生類化語言應(yīng)用,提高語言輸出的豐富性。處理完文本內(nèi)容信息后,進入語篇信息處理,進行主題相關(guān)的詞塊歸類。引導(dǎo)學(xué)生快速閱讀,尋找表達相同主題(發(fā)展或者藝術(shù))的詞和短語,再根據(jù)詞性、用法和結(jié)構(gòu)進行歸類,儲備主題相關(guān)詞匯,豐富語言儲備,提升語言素養(yǎng)。 Assignment: Go online to gather more information about Chinese painting and write a short history of it. 【設(shè)計意圖】結(jié)合所學(xué),遷移運用,根據(jù)實際語境,進行模仿性運用。在此過程中,學(xué)生嘗試借鑒已學(xué)的語言、內(nèi)容、語篇結(jié)構(gòu)和寫作手法來建構(gòu)新文本,實現(xiàn)語篇輸出,同時關(guān)注中西藝術(shù)文化的差別,加深對優(yōu)秀文化的認同,培養(yǎng)文化意識。
本活動旨在落實課時目標3。 The Student Union is looking for three students for a 3-week voluntary program in Guizhou province. The volunteers have got to be high school students, with a persevering personality and experiences in overcoming adversity. The volunteers need to stay, eat and teach with 20 pupils in a small school up on the hill of a village. There are no facilities but desks and a blackboard in the school. And there is no take-away food to be bought anywhere; the only way to feed yourself is to cook. You’re interested in applying. Write your application letter introducing what adversity you have ever overcome and how persevering you are as well as what you want to do when at work. Dear Student Union,【設(shè)計意圖】此任務(wù)旨在遷移一、二課時所學(xué),解決實際問題。學(xué)生對比自己經(jīng)歷過的挑戰(zhàn)或挫折,寫信給學(xué)生會申請前往貴州擔(dān)任短期支教教師,把個人以前是怎么戰(zhàn)勝挫折的經(jīng)過書寫出來。結(jié)合所學(xué),遷移創(chuàng)新,分析解決自身實際問題,在真實情境中學(xué)生通過仿寫進行主題語言的精確輸出。完成任務(wù)的過程中,能較多地使用已學(xué)語言、內(nèi)容、結(jié)構(gòu)和寫作手法來描述自己面對挫折的處理方式、態(tài)度和應(yīng)有的品質(zhì),近一步激發(fā)學(xué)生樹立正確的價值觀,學(xué)會逆境出人才,堅忍不拔,從容不迫,又做到謙讓、分享和合作。課后學(xué)生修正習(xí)作,再次提交。
本單元閱讀文本介紹了幾種簡單的英語詩歌形式,旨在讓學(xué)生能理解和欣賞英語詩歌的美,包括形式美、內(nèi)容美、意義美,培養(yǎng)審美情趣,并從作品的意義美中獲得積極的人生態(tài)度和價值觀念啟示。 該文本是一則典型的說明性文本,用簡單易懂的語言向英語詩歌的初學(xué)者們介紹了五種比較簡單的英語詩歌形式。文題“A Few Simple Forms of English Poems”是整個文本的核心話題。正文內(nèi)容共七段,按“總—分—總”建構(gòu)。第一段為總起段,概述了英語詩歌的創(chuàng)作原因以及主要特點,涉及了形式、內(nèi)容、意義等方面賞析英語詩歌的幾個主要維度;第二段至第六段分別介紹了童謠、清單詩、五行詩、俳句和唐詩五種英語詩歌形式;第七段收尾,鼓勵讀者嘗試英語詩歌創(chuàng)作。 在進行文本教學(xué)設(shè)計時,要引導(dǎo)學(xué)生梳理關(guān)于與詩歌要素和詩歌賞析有關(guān)的話題類語言,既包括format、rhythm、subject、image等名詞,也包括have a strong rhythm、be made up of、contain、consist of、convey這樣的動詞和動詞短語。
本活動旨在落實課時目標3。 Think about the following questions and talk about your own attitude in pairs.Q1: As for this topic,what impresses you the most in the passage?Q2: What do you think of the future of China’s further exploration in sea? Are you in favor of the further exploration?Why or why not? 【設(shè)計意圖】該活動是一個完全開放性的活動,每個學(xué)生都會有不同的答案。運用遷移所學(xué),自由口頭表達自己對海洋探索的態(tài)度。對于中國海洋探索的未來,每個人的想法是不一樣的,有樂觀,有擔(dān)憂,有認為值得投入,也有認為不值得付出太大代價,這里給學(xué)生自由表達的空間只要學(xué)會有支撐自己觀點的事實就可以了,進一步培養(yǎng)學(xué)生批判性思維和正確的價值觀。 Assignment: 此任務(wù)旨在遷移一、二課時所學(xué),培養(yǎng)學(xué)生辯證分析問題的能力。 Write about your idea of the future of China’s sea exploration. And add your attitude towards the effort China have made in sea exploration. You’re expected to use the language and the writing technique learnt in the passage.
【核心素養(yǎng)提升點】學(xué)會將抽象信息進行可視化表達,提高信息處理能力和分析、推理等高階思維品質(zhì);在跨文化交際中學(xué)會以國際視野接受和包容不同的文化。 5.Read Paragraph 2, draw a mind map and answer the questions. Q1:What did Jo learn about Tombe’s life? Q2:What kind of life do the natives lead? Read paragraph 2-5 and draw a mind-map. (Focus on accommodation, possession, diet and belief) 【設(shè)計意圖】引導(dǎo)學(xué)生利用思維導(dǎo)圖和問題鏈等形式來厘清當(dāng)?shù)厝说纳罘绞?,更好地處理和歸納信息 【核心素養(yǎng)提升點】提高信息處理能力、分析和歸納能力,包容異國文化、擴展國際視野。 6.Read Paragraph 3 and answer the questions. Q1:What was Jo’s feeling upon arriving her own home? Q2:Why would she feel that way? Q3:Do you think “It was such a privilege to have spent a day with Tombe’s family”? 【設(shè)計意圖】通過提問,讓學(xué)生理解Jo的苦并快樂的心情,并通過對“It was such a privilege to have spent a day with Tombe’s family”這句話的理解,體驗志愿者生活的偉大。 【核心素養(yǎng)提升點】學(xué)會對信息的綜合和歸納,從而理解作者所表達的觀點。 Activity4: Summarize the change of Jo's feelings
科學(xué)家預(yù)測,就地區(qū)而言,位于低緯度的大部分國家,農(nóng)作物的產(chǎn)量將減少;而位于高緯度的國家,農(nóng)作物產(chǎn)量有可能增加。由于不少發(fā)展中國家位于低緯度地區(qū),因此,氣候變化的這種區(qū)域差異性,可能會使發(fā)展中國家所面臨的問題更為嚴峻。板書:3全球變暖將加劇水資源的不穩(wěn)定性與供需矛盾。介紹:全球變暖會影響整個水循環(huán)過程,可能使蒸發(fā)加大,改變區(qū)域降水量和降水分布格局,增加降水極端異常事件的發(fā)生,導(dǎo)致洪澇、干旱災(zāi)害的頻次和強度增加,以及地表徑流發(fā)生變化。隨著徑流減少,蒸發(fā)增強,全球變暖將加劇水資源的不穩(wěn)定性與供需矛盾。轉(zhuǎn)折:既然全球變暖會引起很多不利影響,那么作為人類應(yīng)如何面對這一挑戰(zhàn)呢?這就是我們要討論的第三個問題。板書:三、氣候變化的適應(yīng)對策討論:請大家閱讀結(jié)合教材P53氣候變化的適應(yīng)對策部分討論人類應(yīng)如何面對全球變暖這一問題 呢?
1.改善城市環(huán)境:治理河流、控制大氣污染物、大力加強綠化建設(shè)為改善城市環(huán)境,上海市全面展開對大氣、河流、噪聲等多方面的治理工作。如蘇州河的治理、降低城市污染物濃度、加強綠化建設(shè),截止1990年,市區(qū)綠化覆蓋率達到20.3%。2.改善城市交通、改善居住條件擴寬主干道,修建環(huán)城公路,修筑了南浦大橋和揚浦大橋,新修城市高架公路和地鐵,改造住宅。3.控制城市規(guī)模建立衛(wèi)星城,開發(fā)新區(qū),有效地控制城市中心區(qū)的規(guī)模。思考:什么時候許多國家采取措施保護和改善城市環(huán)境?你認為可以采取哪些措施來保護和改善城市環(huán)境?上海市保護和改善城市環(huán)境的措施:上海的衛(wèi)星城有哪些?上海新建了哪個新區(qū)?目前浦東新區(qū)在上海的地位如何?建立衛(wèi)星城和開發(fā)新區(qū)可以起到什么作用?上海市為改善交通條件,做了哪些工作?
1.生產(chǎn)上的聯(lián)系:有投入——產(chǎn)出的關(guān)系工業(yè)生產(chǎn)的過程復(fù)雜,工序繁多,往往需要經(jīng)過多家工廠的加工才能完成一種產(chǎn)品的生產(chǎn)過程。因此,在這些工廠之間就存在著產(chǎn)品與原料的聯(lián)系。一家工廠生產(chǎn)的產(chǎn)品是另一家工廠的原料,這兩家工廠之間就形成了工序上的工業(yè)聯(lián)系。2.非生產(chǎn)上的聯(lián)系:如地理空間上的聯(lián)系布局在同一個工業(yè)區(qū)內(nèi),共同利用工業(yè)區(qū)的道路、供水、供電、通信等基礎(chǔ)設(shè)施以及其他生產(chǎn)、生活服務(wù)設(shè)施,或者共同利用當(dāng)?shù)亓畠r的勞動力,形成了空間利用上的工業(yè)聯(lián)系。我國許多地方的經(jīng)濟技術(shù)開發(fā)區(qū)就是建立在這種工業(yè)聯(lián)系基礎(chǔ)上的。(二)工業(yè)集聚1.形成具有工業(yè)聯(lián)系的一些工廠往往近距離地聚集起來,形成工業(yè)集聚現(xiàn)象。2.工業(yè)集聚可獲得效應(yīng)(1)工業(yè)集聚可以加強企業(yè)間的信息交流和技術(shù)協(xié)作,降低中間產(chǎn)品的運輸費用和能源消耗,進而降低生產(chǎn)成本,提高生產(chǎn)效率和利潤,取得規(guī)模效益。
1.國家石油價格上漲,導(dǎo)致依賴于國際石油而建立起來的日本重化工業(yè)的制造成本提高,產(chǎn)品價格相應(yīng)提高,削弱了日本重化工產(chǎn)品在國際市場上的競爭力。2.日元 的大幅度升值,意味著日本產(chǎn)品在國際市場上的價格大幅度提高。例如,同樣的日本產(chǎn)品,如果原來在國際市場上賣1美元,日元升值1倍后其在國際市場上的售價就達2美元。所以,以國際市場為依托的日本傳統(tǒng)產(chǎn)業(yè)只好紛紛向海外轉(zhuǎn)移。3.自身市場滿足不了發(fā)展需求,國際市場上亞洲發(fā)展中國家和地區(qū)的同類產(chǎn)品具有明顯的價格優(yōu)勢。所以,日本企業(yè)在其國內(nèi)發(fā)展的空間很小。4.勞動力價格高反映為產(chǎn)品的價格高,而勞動力數(shù)量又滿足 不了企業(yè)進一步擴展對勞動力的需求。所以,日本從事傳統(tǒng)產(chǎn)業(yè)的國內(nèi)企業(yè)生產(chǎn)受勞動力價格和數(shù)量的雙重制約。5.促進日本企業(yè)生產(chǎn)的區(qū)位選擇向國土的南、北部和海外擴展。6.“技術(shù)立國”的政策明顯對傳統(tǒng)產(chǎn)業(yè)在國內(nèi)生產(chǎn)不利,即企業(yè)生產(chǎn)要么向知識技術(shù)密集型轉(zhuǎn)換(這需要大量的投資),要么轉(zhuǎn)向海外。
(一)自然災(zāi)害監(jiān)測系統(tǒng)1.概念:自然災(zāi)害監(jiān)測系統(tǒng)是由國家、區(qū)域及地方等各級組織,通過不同平臺對自然災(zāi)害進行監(jiān)測和分析的網(wǎng)絡(luò)系統(tǒng)。2.作用:災(zāi)前預(yù)警、災(zāi)中跟蹤、災(zāi)后評估以及提出減災(zāi)決策方案3.世界和我國災(zāi)害監(jiān)測系統(tǒng)的發(fā)展情況①已經(jīng)形成了遍布世界各地、相互交織的災(zāi)害監(jiān)測和預(yù)警網(wǎng)絡(luò)。②我國已經(jīng)運用現(xiàn)代科學(xué)技術(shù)建立起各種自然災(zāi)害監(jiān)測系統(tǒng)(二)遙感技術(shù)在自然災(zāi)害監(jiān)測中的作用1.遙感(RS)技術(shù)的特點:觀測范圍廣、信息獲取量大、獲取速度快、實時性好和動態(tài)性強等。從空間尺度看,遙感具有全球觀測能力,可從多波段、多時相和全天候角度獲得全球自然災(zāi)害的觀測數(shù)據(jù);從時間尺度看,在遙感平臺上能夠?qū)Φ厍蜻M行同步觀測,可獲得地球表層及其瞬間變化的災(zāi)害信息。
5.對土星五號火箭和登月艙的質(zhì)疑現(xiàn)代航天飛機只能把20噸載荷送上低軌,而當(dāng) 年的土星五號卻能輕而易舉地把100噸以上載荷送上地球軌道,將幾十噸物體推出地球重力圈,為什么后來卻棄而不用,據(jù)說連圖紙都沒有保存下來?6.溫度對攝影器材的影響月面白天可達到121°C,據(jù)圖片看,相機是露在宇航服外而沒有采用保溫措施的。膠卷在66°C就會受熱卷曲失效,怎么拍得了照片?這些人士認為,對以上這一切美國政府一直沒個 交代,而知情者由于擔(dān)心生活和安全受到影響,甚至可能直接遭到了脅迫,至今對此沉默不言。但相信不久的將來,誕生于美蘇太空競賽年代的“登月騙局”定會水落石出。反駁不過,也有許多人認為“阿波羅”登月計劃不可能造假:首先因為該計劃當(dāng)時是在全球?qū)崨r轉(zhuǎn)播的,近億人親眼看到。另外,宇航員還從月球帶回了一些實物,如巖石。
知識和技能 1、 了解區(qū)域工業(yè)化和城市化之間的關(guān)系,以及它們對區(qū)域社會經(jīng)濟發(fā)展所起的作用 。2、分析導(dǎo)致珠江三角洲工業(yè)化和城市化快速推進的諸多思想束縛,并通過比較,認識到對外開放政策是其中的關(guān)鍵因素。3、 比較珠江三角 洲的 區(qū)工業(yè)化進程的兩個主要階段,歸納出不同時期的主要發(fā)展特點,并能夠結(jié)合具體案例分析工業(yè)化進程對城市化的巨大推動。 4、分析珠江三角洲地區(qū)工業(yè)化和城市化進程中的問題,并嘗試評價目前的一些調(diào)整措施和發(fā)展方向。5、通過分析我國珠江三角 洲地區(qū)工 業(yè)化、城市化的發(fā)展階段、問題與對策,了解區(qū)域工業(yè)化和城市化的推進動力和發(fā)展規(guī)律。過程與方法 利用扮演不同的社會角色來談對珠江三角洲地區(qū)未來經(jīng)濟和城鎮(zhèn)發(fā)展的設(shè)想和建議,反饋學(xué)生知識、能力、價值觀發(fā)展情況和效果, 培養(yǎng)學(xué)生對所學(xué)所得的運用能力,并為學(xué)生的創(chuàng)新精神的發(fā) 展營造有利氛圍。情感、態(tài)度與價值觀1、通過鼓勵學(xué)生主動獲 取資料的做法,關(guān)注學(xué)生實踐能力、綜合思維能力及終身學(xué)習(xí)能力的訓(xùn)練。
彗星簡介:(1)云霧狀的獨特外貌,質(zhì)量很??;(2)主要由冰物質(zhì)構(gòu)成(含塵埃、水、甲烷、二氧化碳等),有人稱它為“臟雪球”;(3)結(jié)構(gòu)分彗核、彗發(fā)、彗尾(分離子尾、塵埃尾),彗星在遠離太陽時,只有一個冰凍的彗核,當(dāng)行進太陽時,組成物質(zhì)升華而形成彗發(fā),在太陽風(fēng)的吹拂下,背向太陽的一側(cè)出現(xiàn)彗尾,遠離太陽時,彗尾消失,尾永遠背向太陽;(4)目前已經(jīng) 發(fā)現(xiàn)了1600多顆彗星,最著名的就是哈雷彗星,1985~1986 年,曾回歸;(5)彗星的公轉(zhuǎn)周期各不相同,相差極大,有的幾十年,有的幾百年,哈雷彗星的公轉(zhuǎn)周期為76年。學(xué)生討論回答,然后速讀課文“流星體”?!締l(fā)引導(dǎo)】行星際空間是否是“真空”狀態(tài)?行星際空間分布著極其稀薄的氣體和塵埃,稱為行星際物質(zhì),行星際物質(zhì)的來源——太陽風(fēng)、星際沖撞……