一、教材分析:《田忌賽馬》是小學語文五年級下冊的一篇課文。這篇課文主要講了戰(zhàn)國時期齊國大將田忌和齊威王賽馬,田忌連輸三場,孫臏看了比賽后幫助田忌調(diào)換馬的出場順序,取得了第二次比賽的勝利,表現(xiàn)了孫臏的足智多謀。全文按照時間的先后順序,可以分為“初戰(zhàn)失敗”“孫臏獻計”“再賽獲勝”三部分,這個故事啟發(fā)我們做事要仔細觀察,善于思考。本課時是第二課時,在第一課時學生讀通課文,學會生字新詞,了解課文大意,了解第一次賽馬的經(jīng)過、結(jié)果的基礎(chǔ)上,我設(shè)定本課的教學目標為:二、教學目標:“認知”目標:理解課文內(nèi)容,體會孫臏的足智多謀,積累詞語?!澳芰Α蹦繕?抓住人物的神態(tài)、語言來感悟人物的情感及性格特點,從而有感情朗讀課文?!扒楦小蹦繕?懂得在學習生活中仔細觀察、善于分析,才能找到解決問題的好方法。教學重點:理解課文內(nèi)容,體會孫臏的足智多謀。教學難點:理解孫臏為什么能想出這樣的好主意。
師:相信我能行,這樣行不行?(播放課本53頁插圖)“老師宣布下周長跑比賽,東東覺得自己個子高,腿長,肯定跑得快,就不打算練習了”師:東東相信自己行,所以不用練習,你們有什么看法?生:相信自己能行,也要加強練習呀!生:東東的同學不僅相信自己行,還主動練習,這樣東東的同學就會贏,東東可能會輸。生:光說不練,不是真的行!師:同學們說得真是太好了,不能只說行,努力才能行啊。成功靠的不僅是自信,更多的要靠努力、方法和汗水。明白了這些道理,你們才能真正做到”我能行:!師:有沒有信心大聲的朗讀兒歌《我能行》?(學生齊讀兒歌總結(jié))(三)、作業(yè)拓展師:現(xiàn)在請拿出寫有“我能行”的紙飛機,從今天開始,如果每天你都能堅持做到紙飛機上“我能行”的事情,就給自己畫一個笑臉。堅持一周,都做到,就把紙飛機拿到空曠的地方努力的放飛,并大聲的對著天空說:我能行!(提醒學紙飛機掉在地上要撿起來,注意環(huán)保)
(4)寫第三間小屋時作者為什么說“在我們的小屋里,住著所有我們認識的人,唯獨沒有我們自己”?明確:這是一個信息高度發(fā)達的社會,我們能從不同渠道接受各種紛繁復雜的信息,漸漸,有的人就被這個信息社會所同化了,常常隨波逐流,用他人的觀點來肯定事物的價值,常常以為眾人所追求的就是他們自己想要的。于是別人的思想、外在的信息代替了他們自己的思想,使自己成為缺乏思想和思考的人,所以說“唯獨沒有我們自己”。(5)你認為在第三間精神小屋中應(yīng)該怎樣“安放我們自身”呢?明確:安放自身需要思考,擁有獨立的思想。(6)請你結(jié)合日常生活,說說你是否嘗試過如此構(gòu)建“精神的三間小屋”?!窘虒W提示】引導學生在對“精神的三間小屋”的理解基礎(chǔ)上來審視生活,從而達到反思生活,審視自我精神世界,建構(gòu)自我精神世界的目的。
第三節(jié),把“愛”比作“四月的花”和“月圓”,表現(xiàn)了愛的美與莊嚴。第四節(jié),用“雪化后那片鵝黃”“初放芽的綠”“白蓮”表現(xiàn)了愛的生命力和純凈。第五節(jié),“一樹一樹的花開”“燕子呢喃”表現(xiàn)愛之深,情之切。3.詩人通過不同的感官來描寫“四月”所獨有的景物,試結(jié)合內(nèi)容進行分析。明確:通過視覺描寫:“黃昏”“星”“云煙”“花”。通過聽覺描寫:“笑響”“四面風”“燕子呢喃”。通過觸覺描寫:“風的軟”“暖”。多角度展開描寫,表現(xiàn)了詩人的“愛之深,情之切”。能引導讀者調(diào)動多種感官去感受詩人心中的“愛”,給讀者以感染?!窘虒W提示】指導學生結(jié)合詩人筆下的意象進行分析。目標導學三:品讀詩句,把握詩歌藝術(shù)特色探究:“新月派”的重要成員之一聞一多先生曾提出了“三美原則”,即“音樂美、繪畫美、建筑美”,奠定了新格律詩派的理論基礎(chǔ)。本詩既是新格律詩的典范,它是否表現(xiàn)了“三美”原則?是如何表現(xiàn)的?
分析:“襤褸”一詞是對于勒的外貌描寫,點明他生活的貧困,處境的艱難。②他又老又臟,滿臉皺紋,眼光始終不離開他手里的活兒。分析:再次描寫于勒的外貌,充分說明他歷盡磨難,飽經(jīng)滄桑,窮困潦倒。③我看了看他的手,那是一只滿是皺紋的水手的手。我又看了看他的臉,那是一張又老又窮苦的臉,滿臉愁容,狼狽不堪。分析:第三次描寫于勒的外貌,準確地表現(xiàn)出他此時的窮困潦倒,暗示他不幸的遭遇,竭力渲染他的悲慘境地。2.本文通過神態(tài)、語言、動作描寫揭示人物心理活動,刻畫人物性格,找出這些句子來進行分析。明確:菲利普認出賣牡蠣的窮水手就是于勒時,“突然好像不安起來”,這是心理驟然緊張所致;“他向旁邊走了幾步”,是想躲開于勒的目光,怕于勒認出自己來;“瞪著眼”看女兒、女婿,是怕他們察覺出這個秘密。這一系列神態(tài)、動作描寫,層次分明地寫出了人物緊張、恐慌以至失魂落魄的心理狀態(tài)。
小說精心設(shè)計,以“我”回憶往事的視角來敘述,其他人物的態(tài)度和行動,都是從“我”的眼里看到的;對其他人物的感受和評述,也都是從“我”的角度表達的。這樣寫既有利于拉開適當?shù)木嚯x,為小說主題的展開留下空間,同時也有利于安排情節(jié)的曲折變化,避免多余的解釋說明?!驹O(shè)計意圖】內(nèi)容決定形式,形式服務(wù)內(nèi)容。在逐層深入理解課文時,穿插對寫作技巧的講解與點撥,要求學生在朗讀中細細品味,有助于學生深入學習與運用。四、拓展,悟人生1.拓展閱讀課外閱讀《項鏈》。2.發(fā)散思維有一首歌里唱道:“有錢沒錢,回家過年?!奔偃缒闶侨羯?,當你走到于勒面前時,你會對他說些什么呢?【設(shè)計意圖】學以致用,啟迪人生智慧,形成正確的人生觀、價值觀。結(jié)束語:金錢扭曲了人性,撕裂了親情。觀照生活,思索人生,我們會發(fā)現(xiàn)親情帶來的溫暖遠勝于金錢,讓我們一起說——讓人間充滿愛!
(1)Have you ever been to …? Yes, I have. / Yes, I have ever been to …No, I haven’t. / No, I have never been to …(2)When did you go there? I went there last year. (3)I have never been to a water park. Neither have I. I have ever been to an amusement park. So have I. (4)How long have you been studying English? I’ve been studying English since nine o’clock. I’ve been studying English since I came back home. I’ve been studying English for five hours. (5)What’s that? It’s an amusement park in Japan. I’ve never been to an amusement park like it before. It’s fun to learn another language. Let’s go tonight. Isn’t this great?space museum, amusement park, water park, South America, Peru, Holland, European culture, tour guide, flight attendant, musical instrument, more than, be from, get to, take lessons, neither, discover, graduate, change
說明:在幫Li Lei提建議的同時,教育學生如何學好英語。第三課時教學目標1. 語言目標:a) 詞匯: Original, in style, haircut, the same as.b) 語言結(jié)構(gòu):My friend wears the same clothes and has the same haircut as I do.2. 能力目標:大多數(shù)學生能夠談?wù)撟约合矚g哪種服裝,提高查找信息的能力。3. 情感目標:學會如何與朋友相處,要有自己對時尚的看法。教學重點掌握一些重要詞匯。教學難點學會談?wù)搯栴},并能提出書面建議?!艚虒W突破首先針對Erin的問題,提出個人的建議,模仿2c部分的對話展開雙人交際Pair-work;聽老師誦讀3a部分的信件,并找出LEFT OUT的問題所在;學生完成3b部分的內(nèi)容,給Left Out提出書面的建議;學以口頭形式提出自己目前存在的某個問題,講給大家聽,讓同學們給自己提出一個建議,并作筆錄;學生兩、三個人分成一組,隨意性地進行口語交際,談?wù)揚14的第4部分的某個問題,相互交換意見。
區(qū)分賓語從句、定于從句和狀語從句賓語從句和狀語從句,都叫做主從復合句。賓語從句主要是中考必考的,是初中階段必掌握的從句,賓語從句主要是掌握三要素,所謂賓語從句,就是賓語在主從復合句當中充當賓語的一個句子,叫做賓語從句。主句的謂語動詞是及物動詞,后面如果是詞或者是短語的話,是簡單句,如果是句子的話,肯定是賓語從句。I know that he good at English.就是賓語從句,三要素,一要素是要注意連詞,連詞一共學了三類連詞,一類連詞是that口語當中可以省略,就像剛才說的那一句,I hear he is good at English.還有疑問代詞、疑問副詞,how where when,疑問代詞、疑問副詞。還有一類連詞weather是否的意思,不是狀語從句當中的如果,這一定要和如果區(qū)分開,這是是否。I don't know if he interested at English。賓語從句要注意if是連詞。第二要素是語序,要用陳述舉語序。比如說你家有幾口人,我們都說How many people are there in you family?但是這是簡單句,一旦說成賓語從句,你可以告訴我你家有幾口人嗎?Could you tell me how many people there are in you family ?
"Hello! Welcome to English class! Introduce yourself. Meet your new classmates." That's what the teacher says. What do you say? "Oh no!" It can be difficult talking to new people. But it can be fun, and you can make friends. How do you do it? Make small talk. Small talk is polite conversation. "Wang Nan is a great pingpang player, isn't she?" "I'd love to meet her, wouldn't you?" "It's been raining a lot, hasn't it?" Tag questions are a form of polite speech. To make small talk successfully, you should know how to make them. You should also know what topics to talk about. Try to learn this unit carefully. The next time you're in English class, you'll find out. Making small talk's easy, isn't it? (“你好!歡迎你!請做一下自我介紹。認識一下你的新同學?!蓖ǔT谡n上老師會這樣說。你會說什么呢?“噢,不!”與陌生人談話太困難了。但是這也很有意思,并且你還能交到朋友。你該怎么做呢?閑聊。閑聊指得是禮貌的對話?!巴蹰且粋€很棒的乒乓球運動員,不是嗎?”“我希望自己能認識她,你呢?“今年的雨水很多,不是嗎?”反意疑問句是一種禮貌用語。為了使得談話成功,你應(yīng)該知道怎樣去進行閑聊。你還應(yīng)該知道與不同的人該談?wù)撌裁礃拥脑掝}。認真的學習這個單元吧,下次在英語課上,你會發(fā)現(xiàn)與大家展開談話是一件很容易的事情,不信我們來試試。)
This activity introduces some new vocabulary and provide oral practice using the target language.Task 1 . Ask four students to stand in front of the class, and the teacher asks them the following questions as a reporter.1.What are you going to do when you grow up?2.What are you going to do next week?3.What are going to do after school?The students will give different answers, then ask a good student to report what they said.I am going to e a doctor.What did she say?----------She said she was going to be a doctor.I am going to have a party on Friday night.What did he say?-------He said he was going to have a party on Friday night.I am going to do my homework.What did she say ?------ She said she was going to do her homework.I am going home after school.What did she say?-----She said she was going home after school.Say In this unit we are going to learn to use words like to report what someone said.Task 2. Read the instructions. Then ask a student to read the four questions. And write the words on the Bb. Explain what soap opera is.Task 3. Ask the students to Look at the pictures, point out the TV screens in the picture. Ask one girl to read what Marcia said.What did Marcia say? She said She said she was having a surprise party for Lana on Friday night. Repeat the other pictures in the same way.Activity3. Listen and number the pictures in activity 1a.
Step Ⅱ Show the new words on the screen and teach the new words. Read the new words to students and ask them to repeat.Step Ⅲ 3aThis activity introduces new vocabulary and provides reading practice using the target language.In this activity first look at the four pictures.T: What can you see in the pictures?Ss: Four snow globes.T: Right. There are four snow globes in the pictures. And what are they?Ss: They are a monster, two polar bears, two penguins and a birthday cake.Write these words on the blackboard: snow globe; monster; polar bear; penguin and birthday cake. Read them to the class and ask students to repeat each one. Make sure students understand each word.Use a computer to show the E-mail message on the screen and read the message to students.Get students to read the e-mail on their own, and then draw lines connecting each snow globe and its description.Correct the answers.AnswersA line should connect each snow globe picture with the words that describe it in the letter.Step Ⅳ 3bThis activity provides writing practice using the target language.First review Activity 2a on Page 47.Then ask students to complete the message according to Activity 2a.Some partial sentences are given to students. Write about one person's collection.When students work, walk around the room checking the progress and offering help as needed.When they finish, ask some students to read their messages to the class.
(一).知識方面: 1.培養(yǎng)學生能運用過去進行時來描述、談?wù)撨^去某個時間正在發(fā)生的事情或動作的意識和能力,能就過去某個時間正在發(fā)生的動作做出正確的描述。 2.培養(yǎng)學生的想象力和角色扮演的合作能力。 3.培養(yǎng)學生講述過去發(fā)生的事情經(jīng)過的能力。能正確運用一般過去時來講述故事。 (二).技能方面: 1.本單元的語言目標是Talk about past events and tell a story(談?wù)撨^去的時間和講述一個故事),圍繞這一目標,要涉及句型: What were you doing when the UFO arrived? ----I was sitting in the barber’s chair. The barber was cutting my hair. 因此必須學習standing、studying、cleaning、sleeping、cooking、making、eating、cutting、等表示地點的詞,以便為上述句型提供語言材料。2.學習過去進行時的有關(guān)知識。Was/were+現(xiàn)在分詞,是該時態(tài)的表達式。 3.在學習過程中,要區(qū)分The boy was walking down the street when the UFO landed.和While the boy was walking down the street, the UFO landed.這兩種由when和while引導的狀語從句的句型結(jié)構(gòu)。注意它們的不同。
教師帶領(lǐng)學生復習有關(guān)描述寵物的詞匯,采用教師提問學生回答的方進行。如:T:What animals do you think would be good pets?What animals do you think would be bad pets?What do you think are good animals for a six-year-old child?然后學生進行 pairwork 練習。Task two: 師生互動,學習探究 1、播放3a部分的錄音,引導學生一邊聽錄音,一邊跟讀。2、通過聽錄音學生回答以下問題:Why do you think pot-bellied pigs are popular?What are the advantages and disadvantages of keeping such a pet?教師對學生的回答進行及時點評。3.學習范文,學習重點短語,為下步的模仿寫作提供語言素材。T :1. )Have you ever kept a pig as a pet?Do you like pigs? St.:No.…Why don’t you like to keep a pig? St: No.They’re too dirty and lazy(Do you know in some foreign countries like Hollyland, Australia,pigs are the most popular pet.there’s a kind of pig.(圖)it has an interesting name? it ‘s called a pot-bellied pig.) Now,let’s learn an article about this kind of interesting pet.2.)play the tapeSt.:Listen and repeat3.)show some Qs on computer(本子St.: read silently,then answerthe Qs(本子)4.)Ask ss. Close book and retell this passage.(what is a pot-bellied pig? Is it a good or bad pet? ) St.: retell it to each other“A pot –bellied pig is a popular pet now…”5.read the article together.St.:.practice reading
Step 4. Group work (4)1. Ask a pair of students to read the dialogue. Say, This activity provides speaking, listening and writing practice using the target language.2. Ask students to complete the work in groups.3. Check the answers with the whole class. 4. Explain some of the language points. Step 5. Word review (Self check 1)1. Ask students to read the words and the phrases given. 2. Fill in the blanks with proper forms of these words to complete the sentences. 3. Check the answers with the whole class. Homework:Do activity 2 on page 57 after class. Period 6Teaching aims: 1. Teach vocabulary words and the useful expressions. 2. Enable the students to learn etiquette in different culture. 3. Help the students learn how to behave politely in public places and in daily life. Teaching procedures:Step 1. RevisionHelp students to review the function of making requests through a free talk. Then lead them to the topic of etiquette. Explain the meaning of etiquette. Or, ask students to look it up in the dictionary. Step 2. Pre-reading (Section 1)1. Ask students to read the picture and make a list with their partner about how many rules of etiquette can be seen being broken.
尊敬的各位老師,親愛的同學們:大家早上好!感謝八年級(2)班優(yōu)秀升旗手的精心準備,從你們的演講里,我們聽出了真誠、積極、努力和進取,祝你們在今后有更大的進步。不知道同學們還記不記得上周六那一天,早上天氣還是風和日麗,下午就是狂風大作。漫天的黃沙帶著地上的各色塑料垃圾袋一起被狂風卷上天。站在大街上,狂風呼嘯著在身邊肆虐,單薄的身體隨時都有可能被卷入半空,然后摔個半死,我們一定是心驚膽戰(zhàn)的。不知道大家還記不記得XX年5月12日的汶川地震,主震僅持續(xù)96.57秒,就造成69227人遇難,374643人受傷,失蹤17923人。在大自然面前,我們?nèi)祟?,顯得是那樣的渺小。這讓我想到了咱們國家發(fā)生的的自然災(zāi)害,僅XX年,我國多災(zāi)并發(fā),重災(zāi)連發(fā),災(zāi)害強度大,影響范圍廣,人員傷亡多,城鎮(zhèn)受災(zāi)重,重復受災(zāi)、貧困地區(qū)受災(zāi)比例高,農(nóng)業(yè)損失、民房倒塌和基礎(chǔ)設(shè)施損毀嚴重。特別是年初北方大部嚴重寒潮冰雪、西南地區(qū)嚴重秋冬春連旱、4月14日青海玉樹7.1級強震、汛期南方地區(qū)連續(xù)多次嚴重暴雨洪澇、8月8日甘肅舟曲特大山洪泥石流等數(shù)次重特大自然災(zāi)害,造成傷亡人數(shù)之多、災(zāi)情之重、救災(zāi)和恢復重建難度之大歷史罕見,給我國經(jīng)濟社會發(fā)展和人民生命財產(chǎn)安全帶來嚴重影響。全國各類自然災(zāi)害共造成4.3億人次受災(zāi),因災(zāi)死亡失蹤7844人,緊急轉(zhuǎn)移安置1858.4萬人次;農(nóng)作物受災(zāi)面積3742.6萬公頃,其中絕收面積486.3萬公頃;倒塌房屋273.3萬間,損壞房屋670.1萬間;因災(zāi)直接經(jīng)濟損失5339.9億元。
老師們、同學們!端午節(jié),門插艾,香滿堂,吃粽子,灑白酒,龍舟下水喜洋洋。這些,都是曾經(jīng)端午節(jié)上最熱鬧的活動,然而,隨著時代的變遷,社會節(jié)奏的加快,外來文化的大舉入侵,中國人不再眷顧流傳幾千年的中國傳統(tǒng)文化,而是將目光轉(zhuǎn)向了“圣誕節(jié)”“愚人節(jié)”這樣的節(jié)日,面對這種現(xiàn)狀,我們不得不感到悲哀,發(fā)出“端午節(jié)是否不再姓“中”這樣的疑問。當我們還沉浸在西洋節(jié)日的歡聲笑語中時,據(jù)可靠消息說“亞洲某國準備向聯(lián)合國教科文組織申報端午節(jié)為本國的文化遺產(chǎn),目前已將其列入國家遺產(chǎn)名錄。聽到這種消息,中國人除了驚訝只有尷尬,這不僅僅是一個傳統(tǒng)節(jié)日的得失,不僅僅是少了幾項慶祝活動,更重要的是,這是中國的傳統(tǒng)節(jié)日,文化內(nèi)涵豐富,留存著華夏民族獨特的文化記憶,每過一次傳統(tǒng)節(jié)日,就是中華民族凝聚力和向心力的一次加強和洗禮,如今,這個擁有XX多年歷史的傳統(tǒng)佳節(jié)眼瞅著即將成為他國的國家遺產(chǎn),我們將有多么尷尬?
老師們、同學們!端午節(jié),門插艾,香滿堂,吃粽子,灑白酒,龍舟下水喜洋洋。這些,都是曾經(jīng)端午節(jié)上最熱鬧的活動,然而,隨著時代的變遷,社會節(jié)奏的加快,外來文化的大舉入侵,中國人不再眷顧流傳幾千年的中國傳統(tǒng)文化,而是將目光轉(zhuǎn)向了“圣誕節(jié)”“愚人節(jié)”這樣的節(jié)日,面對這種現(xiàn)狀,我們不得不感到悲哀,發(fā)出“端午節(jié)是否不再姓“中”這樣的疑問。當我們還沉浸在西洋節(jié)日的歡聲笑語中時,據(jù)可靠消息說“亞洲某國準備向聯(lián)合國教科文組織申報端午節(jié)為本國的文化遺產(chǎn),目前已將其列入國家遺產(chǎn)名錄。聽到這種消息,中國人除了驚訝只有尷尬,這不僅僅是一個傳統(tǒng)節(jié)日的得失,不僅僅是少了幾項慶?;顒?,更重要的是,這是中國的傳統(tǒng)節(jié)日,文化內(nèi)涵豐富,留存著華夏民族獨特的文化記憶,每過一次傳統(tǒng)節(jié)日,就是中華民族凝聚力和向心力的一次加強和洗禮,如今,這個擁有XX多年歷史的傳統(tǒng)佳節(jié)眼瞅著即將成為他國的國家遺產(chǎn),我們將有多么尷尬?無庸諱言,這些年來,我國的傳統(tǒng)節(jié)日,似乎總離不開吃。端午節(jié)吃粽子,清明節(jié)吃青團,元宵節(jié)吃湯圓,中秋節(jié)吃月餅,春節(jié)更不在話下——大魚大肉讓你吃到不想吃。農(nóng)耕社會對饑餓的恐懼,形成了我國傳統(tǒng)節(jié)日最鮮明的風俗——吃。如今,滿足了溫飽需求的人們正在奔向全面小康,什么時候都有的吃,想吃多少都可以,傳統(tǒng)節(jié)日的吸引力一下子失去了特有的魅力。
【教學目標】1. 理解數(shù)列的通項公式的意義,能根據(jù)通項公式寫出數(shù)列的任意一項,以及根據(jù)其前幾項寫出它的一個通項公式.2. 了解數(shù)列的遞推公式,會根據(jù)數(shù)列的遞推公式寫出前幾項.3.培養(yǎng)學生積極參與、大膽探索的精神,培養(yǎng)學生的觀察、分析、歸納的能力.教學重點 數(shù)列的通項公式及其應(yīng)用.教學難點 根據(jù)數(shù)列的前幾項寫出滿足條件的數(shù)列的一個通項公式.教學方法 本節(jié)課主要采用例題解決法.通過列舉實例,進一步研究數(shù)列的項與序號之間的關(guān)系.通過三類題目,使學生深刻理解數(shù)列通項公式的意義,為以后學習等差數(shù)列與等比數(shù)列打下基礎(chǔ).【教學過程】 環(huán)節(jié)教學內(nèi)容師生互動設(shè)計意圖導 入⒈數(shù)列的定義 按一定次序排列的一列數(shù)叫做數(shù)列. 注意:(1)數(shù)列中的數(shù)是按一定次序排列的; (2)同一個數(shù)在數(shù)列中可以重復出現(xiàn). 2. 數(shù)列的一般形式 數(shù)列a1,a2,a3,…,an,…,可記作{ an }. 3. 數(shù)列的通項公式: 如果數(shù)列{ an }的第n項an與n之間的關(guān)系可以用一個公式來表示,那么這個公式就叫做這個數(shù)列的通項公式. 教師引導學生復習. 為學生進一步理解通項公式,應(yīng)用通項公式解決實際問題做好準備.
課程名稱數(shù)學課題名稱8.2 直線的方程課時2授課日期2016.3任課教師劉娜目標群體14級五高班教學環(huán)境教室學習目標知識目標: (1)理解直線的傾角、斜率的概念; (2)掌握直線的傾角、斜率的計算方法. 職業(yè)通用能力目標: 正確分析問題的能力 制造業(yè)通用能力目標: 正確分析問題的能力學習重點直線的斜率公式的應(yīng)用.學習難點直線的斜率概念和公式的理解.教法、學法講授、分析、討論、引導、提問教學媒體黑板、粉筆