【正文】 ding again and have Ss fill in the the activity provides guided oral practice using the target attention to the conversation in the two Ss to read it to the Ss to work in small a sure everyone talks about at least one of the people on the pairs of Ss to present their conversations to the focus the grammar Ss to say the questions and )Where is your pen pal from?He is from does he live?He lives in Ss to make more sentences with “where, live activity provides reading and spelling out the diagram and explain how it the instructions to the Ss to work in the answers.( United States ,The United Kingdom, Australia,) activity provides guided oral attention to the conversation in the two Ss to read it to the their questions about the Ss to work in several students to perform their conversations for the activity provides listening, speaking, reading and writing practice the the B activity provides reading practice out the language textbooks on the attention to the notebook page with the countries out the sample Ss to write the letter of the correct country in the box next to the title of each language book., ask Ss to work in a student to write his or her answers on the activity provides listening attention to the conversation bubbles in the the recording, number each question you bear on the the recording a second the answers.(Answers: What’s her name?1 /Where is she from?2 /Does she have any brothers and sister? 3 /Does she speak English?) activity provides listening and writing attention to the numbered questions in 2a,ask different Ss to read it out the answer blanks in 2b and the sample the tape and ask Ss to plete the answers the activity provides oral practice each student to work with a and answer one or two exchanges with a work in a pair of Ss to perform the conversation for the activity provides reading and writing attention to the it to the class or a student to read it for to the four questions beneath the Ss work, move help they are finished, ask the questions orally and ask Ss to the correct answers on the board so that Ss can check the spelling and other details of their answers.(,Canada, pen pal in China and a little likes going to the movies with his friends and playing sports.) activity provides reading and writing attention to the letter from Tom out the blanks in the them to find the information to plete the the letter to the class saying “blank”. Ss to write the missing words on the blank lines the activity provides openended Ss to make their own information card and then write an about them to use 3b as an 。學(xué)生配合好，評委的評價就好了。萃取對學(xué)生來說是全新的分離和提純技術(shù)，它是對溶解性規(guī)律的一個應(yīng)用，其原理也在今后鹵族元素和有機物的學(xué)習(xí)中多次體現(xiàn)，在生活中也有多方面的應(yīng)用。二、學(xué)情分析在初中階段學(xué)生已經(jīng)學(xué)習(xí)簡易的蒸餾操作方法，本節(jié)課將在此基礎(chǔ)上對規(guī)范裝置和實驗原理做深入的探討，使學(xué)生更容易接受，已經(jīng)初步了解粗鹽提純的方法，蒸餾的簡易裝置，蒸餾則是在初中簡易操作的基礎(chǔ)上引入使用冷凝管這一較復(fù)雜的操作。（2）知道液體混合物分離和提純的常用方法——蒸餾和萃取，能根據(jù)常見物理的性質(zhì)設(shè)計分離和提純物質(zhì)的方案，并初步掌握其操作技能。五、教學(xué)重點和難點通過對教學(xué)內(nèi)容的分析和教學(xué)大綱的研究，我認(rèn)為本節(jié)課的重點和難點是蒸餾和萃取的掌握和應(yīng)用。（一）課前準(zhǔn)備：學(xué)生的學(xué)習(xí)準(zhǔn)備：預(yù)習(xí)課本上相關(guān)的實驗，初步把握實驗的原理和方法步驟，完成課前預(yù)習(xí)學(xué)案。經(jīng)過觀察、分析、討論后共同得出結(jié)論?？砂凑杖芙狻⑦^濾、蒸發(fā)的實驗操作順序，將它們相 互分離的是（）①B.③④C.②③D.②④，不能用以分離提純物質(zhì)的是（）l 為了使學(xué)生更深的理解所學(xué)知識，掌握實驗技能，我又設(shè)計了課外探究題：（五）課外探究，鞏固新知：多媒體展示：可用于分離或提純物質(zhì)的方法有： ，將分離或提純的編號填入下列各混合物后面的橫線上。多媒體展示：板書設(shè)計:利用液體混合物中各物質(zhì)的沸點不同，用加熱的方法將沸點低的物質(zhì)變