Unit1HowcanwebecomegoodlearnersSectionB2(selfcheck
人教版英语九年级全册练习题：Unit 1 How can we become good learnersSection A(1a～2d)
Unit 1How can we become good learners?第一课时Section A(1a～2d)1．conversationconversation作名词，意为“交谈；谈话”，常用短语：have conversations with sb.和某人交谈；make up conversations 编造对话；conversation topic话题2．辨析aloud，loud与loudly这三个词都可以用作副词，都有“大声地”的意思。
(1)aloud多指提高声音让别人听见，常与read，call等连用，无比较级。
(2)loud侧重指发出的音量大，传得远，常与talk，speak等连用，有比较级。
loud还可作形容词，意为“响亮的，大声的”。
(3)loudly侧重指声音很大，很喧闹，很吵。
如：Reading aloud is a good way to learn English.大声朗读是学习英语的一个好方法。
Can you speak a little louder？你能大点声说话吗？The telephone kept ringing loudly.电话铃一直大声地响。
3．too…totoo…to意为“太……而不能……”。
too后面跟形容词或副词的原形，to后面跟动词原形。
可与so/su ch…that或not…enough to…进行句型转换。
如：He is too young to go to school.他太小了，不能上学。
4．patientpatient作形容词，意为“有耐心的”。
作名词，意为“病人”。
其反义词是impatient，副词形式是patiently。
名词是patience，意为“耐心”。
常用短语：be patient with…对……有耐心be patient to do sth.有耐心做某事be patient of…能忍受/容忍……5．The more you read，the faster you'll be.你读得越多，你读得就越快。
九年级英语unit1 How can we become good learners sectionB教学设计、教案及练习
Section B (2a～2e)
学习目标
1
读懂有关描述“如何成为成功学习者”的文章。 学习重点
重点单词：born，ability，create，brain，active，attention，connect，review，knowledge，wisely 学习难点
通过交流表达和阅读训练，了解好的英语学习习惯和学习策略。
1．Don't worry_about your pet dog.I can take good care of it. 2．We must find_out the truth of the matter now. 3．Even_if he said so，you need not believe him. 4．Would you be_interested_in going to the horse race? 5．Can you tell me what you are looking_for? 课后反思 查漏补缺 收获：________________________________________________________________________ 困惑：________________________________________________________________________
(3)在……有相同之处 have…in__common (4)注意；关注 pay__attention__to
(5)把……与……联系起来 connect…with… (7)查明，弄清楚 find_out 3. I can summarize.(我会总结)
(6)即使 even__if/though
►even if
“疑问词＋动词不定式”结构：英语中，疑问代词 what，who，which 和疑问副词 where，when，why， how 等后面可接动词不定式，这种结构在句中可作主语、宾语、表语等成分。
2020九年级英语全册 Unit 1 How can we become good learners Section A
Unit 1 How can we become good learners? Section A我是通过学习小组来学习的。
They were making a living by selling souvenirs to the tourists.析What/How【链接】What about/Ho w about后还可以接名词或代词作宾语。
What about six o’clock tomorrow morning?明天上午七点钟怎么样?归纳：询问或征求意见或建议的句型还有:(2)aloud为副词,意为“出声地;大声地”,强调发出的声音能让人听见。
例如:It is very important to read aloud in studying English.大声朗读对于学习英语很重要。
3. It’s too hard to understand spoken English.要理解英语口语简直太难了。
(1)句中的it为形式主语,真正的主语为后面的动词不定式短语。
在英语中,不定式作主语时,往往用it作形式主语,而把真正的主语置后。
例如:It’s necessary to get enough sleep every day. 每天有充足的睡眠是非常必要的。
(2)too...to...意为“太……而不能……”,其结构是“too+adj./adv.+to do sth.”,且结构本身表示否定含义。
如:The girl was too frightened to say a word. 那个小女孩吓得一句话也说不出来。
【链接】too...to...常与以下结构作同义句转化:4. I have to finish reading a book and give a report next Monday.我必须读完一本书,下星期一做报告。
(1)动词finish是及物动词,finish sth. 完成某事,finish doing sth. 做完某事。
Unit+1+How+can+we+become+good+learners+Section+AGrammar+Focus-4c(共20张PPT)
d. I like to improve my chemistry by_______
memorizing chemical terms and doing experiments ____________________________________ .
sentence patterns.
b. I like to learn math by__________________ solving new math
problems every day. ______________________________________.
c. I like to practice my physics by___________
Complete these statements. Use information that is true for you.
a.I like to practice my English by taking notes / reading books and newspapers / speaking English with my classmates / memorizing
你是怎样学英语的？ How do you learn English? 你是通过高声朗读 Do you learn English by reading aloud? 来学英语吗？
I learn by studying with 我是通过小组研讨 a 来学习的。 group. Yes, I do. It helps my 是的。这对我的发音 pronunciatish by working with friends.
Unit1 How can we become good learners全单元
用那种方法学到很多
too +形容词或副词+ to do sth.
太…..而不能去做某事
1.他太矮了，而不能够到那个苹果。 too short to reach He is ______ ________ _______ ________ that apple. to catch 2. Tom runs too slowly ___________ (catch ) the early bus.
Now I really enjoy my English class. I want to learn new words and more grammar so that I can have a better understanding of English movies. n. 理 解 那么我可以更好地理解英文电影。
你学习英语的方法
by doing sth.凭借或依靠做某事 ask sb. for sth.向某人寻求某物
a. b. c. d. e.
by working with friends by making word cards by reading the textbook by listening to tapes by asking the teacher for help
2A
Listen and check (✔) the questions you hear.
Questions 1. Does anyone learn English by watching videos 2. Do you have conversations with friends in English? 3. What about listening to tapes? 4. What about reading aloud to practice pronunciation? 5. Have you ever studied with a group?
人教版九年级英语1-14单元课文翻译
Unit1 How can we become good learners?Section A 2d----安妮，我有点紧张，我必须读完一本书，以便下周一作报告。
----听起来不太糟糕。
----但我是一个读书很慢的人。
----一开始只管快速阅读获取文章大意就好了，不要逐字逐句的读，按词组阅读。
----但我很多单词都不懂，我不得不用字典。
----尽量通过阅读上下文来猜测单词的意思，可能你知道的比你预象的要多。
----那听起来很难!----哦，耐心点，这得花时间。
你可以每天通过阅读你喜欢的东西得到提高。
你读得越多，你(阅读的速度)就越快。
Section A 3a我是如何学会学习英语的去年，我不喜欢我的英语课。
每节课像是一个噩梦。
老师说的太快以至于我大多数时候都听不太懂。
因为我糟糕的发音，我害怕问问题。
我只是躲在我的课本后面，从来不说一句话。
后来有一天我看了一部叫做《玩具总动员》的英语电影。
我爱上了这部既激动人心又滑稽有趣的电影！就这样我也开始看其他的英文电影。
虽然我无法听懂那些角色所说的全部内容，但他们的肢体语言和面部表情帮助我理解了意思。
我也意识到我可以通过只听关键词来理解意思。
通过听英文电影中的对话，我的发音也变的更好了。
我发现听一些有趣的内容是学习语言的秘诀。
我还学到了一些有用的句子比如“这简直是小菜一碟”或者“你活该”。
我起初不理解这些句子，但是因为我想理解这个故事，所以我查了字典。
现在我真的喜欢我的英语课。
我想学习生词和更多的语法，那样我对英语电影就能有更好的理解了。
Section B 2b怎么成为一个成功的学习者呢?每个人天生就拥有学习的能力。
但是你能否学习的好取决于你的学习习惯。
研究显示成功的学习者有一些共同的好习惯。
1.培养他们对所学东西的兴趣研究显示，如果你对某事物感兴趣，你的大脑会更活跃而且对你来说长时间地关注那个事物也容易些。
善于学习的人经常把他们需要学的事物与一些有趣的事物联系起来。
Unit 1 How can we become good learners. Section B(
姓名：班级Unit 1 How can we become good learnsSection B一、单项选择1．— Look! Mike does so well in his speech.— Yes, he has a(n) ________ for public speaking.A．eye B．gift C．answer D．attention【答案】B【详解】句意：——看！迈克的演讲做得很好。
——是的，他有公开演讲的天赋。
考查名词辨析。
eye眼睛；gift天赋；answer回答；attention注意力。
根据“Mike does so well in his speech.”可知，有天赋，所以做得好，故选B。
2．The high-speed train has __________ travel time between Beijing and Shanghai from over 9 hours to around 5 hours.A．increased B．reduced C．taken D．spent【答案】B【详解】句意：高铁将北京和上海之间的旅行时间从9个多小时减少到5个小时左右。
考查动词辨析。
increased增长；reduced减少；taken带走，花费（时间）；spent花费。
根据“from over 9 hours to around 5 hours”可知时间减少了，用reduced符合语境。
故选B。
3．My best friend is really________. She likes to attend different activities after school.A．quiet B．honest C．lazy D．active【答案】D【详解】句意：我最好的朋友非常活跃。
她喜欢放学后参加不同的活动。
考查形容词辨析。
quiet安静的；honest诚实的；lazy懒惰的；active活跃的。
Unit 1 how can we become good learners Section B 知识点总结
九年级英语知识点归纳总结Unit 1 How can we become good learners2ndpal /pæl/ n. 朋友；伙伴pen pal 笔友grammar /græmə(r)/ n. 语法repeat /ripi:t/ v. 重复；重做note /nəut/ n. 笔记；记录v. 注意；指出pattern /pætn/, /pætən/ n. 模式；方式physics /fiziks/ n. 物理；物理学chemistry /kemistri/ n. 化学partner /pa:(r)tnə(r)/ n. 搭档；同伴pronounce /prənauns/ v. 发音increase /Inkri:s/ v. 增加；增长speed /spi:d/ n. 速度v.加速ability /əbiləti/ n. 能力；才能brain /brein/ n. 大脑active /æktiv/ adj. 活跃的；积极的connect /kənekt/ v. （使）连接；与⋯⋯有联系connect …with 把⋯⋯和⋯⋯连接或联系起来overnight /əuvə(r)nait/adv. 一夜之间；在夜间review /rivju:/ v. & n. 回顾；复习knowledge /nɔlidʒ/, n. 知识；学问wisely /waizli/ adv. 明智地；聪明地知识点1.make mistakes in 在……方面犯错误2.have trouble/difficulty/problems in doing sth干...有困难3.from time to time 一次又一次4.on the way to school=on one’s way to schoolon the way home=on one’s way home在...的路上5.talk to sb= talk with sb 与某人说话6.talk about 谈论，议论，讨论7.be born with 天生具有the ability to do sth.. 做某事的能力8.whether or not 是否9.depend on 取决于；依靠10.Learning habits 学习习惯11.have ... in common 在...方面有共同点12.be interested in 对...感兴趣13.pay attention to doing 注意；关注Look forward to doing14.active ---more active--- the most active15.connect …with 把⋯⋯和⋯⋯连接或联系起来16.get bored 感到厌烦17.be stressed out 焦虑不安的18.Practice makes perfect. 熟能生巧19.Succeed in doing sth. 成功干...success n. successful adj. successfully adv.20.learn from 向... 学习21.review= go over22.explain sth to sb 向...解释...23.find out the answer 找出答案24.Learning is a lifelong journey.学习是一生的旅程。
2023九年级英语全册Unit1HowcanwebecomegoodlearnersSectionB
(天生的)
artist.
答案
1.pronounce 句意:我不是很懂薇拉的话,因为她有几个单词发音不清晰。空前有didn‘t, 应用动词原形。 2.review 句意:如果你更早一些复习这些重点,你将会在考试中做得更好。 3.active 句意:我认为老年人不能像年轻人那样活跃。not so...as..."不像……那样……"。 4.ability 根据汉语提示及was可知,空处应填ability。 5.born 句意:南希5岁就开始绘画,她是一个天生的画家。born"天生的"。
of the Times"?
—Yes. She
the first free high school for girls in mountain areas and has helped
more than 1,800 students to go to college.
2.
your notes carefully and it is useful for your study.
为Co第mm三u人ni称st P单ar数ty,谓of 语Ch动in词a. 应用第三人称单数形式。
7.brain(s) brain表示"大脑"时为可数名词,此处用单复数均可。
8.create 根据空后的"we enter"可知,本句为一般现在时,故填create。
9.speed 句意:曲春雨、范可新、张雨婷、武大靖和任子威在2 000米短道速滑混合团
students’ interest in our traditional culture.
A. stop
B. increase C. complete
Unit1 Howcanwebecomegoodlearners？SectionA(1a-2d)教案
（4）角色扮演中的语言流畅性：学生在角色扮演时可能因为紧张或不熟悉语境而出现语言表达不流畅的情况。
-难点举例：学生在角色扮演时可能会忘记使用学到的表达，或者表达时出现语法错误。
在教学过程中，教师需针对上述重点和难点内容，采取不同的教学策略和方法，如通过重复练习、真实情境模拟、同伴互助和即时反馈等，帮助学生克服难点，确保学生对核心知识的理解和掌握。
三、教学难点与重点
1.教学重点
（1）核心语言知识：本节课的核心内容为一般现在时态的运用，以及与学习方法相关的词汇和表达，如“listen carefully”，“take notes”，“practice speaking”等。
-学生需要能够正确使用一般现在时描述学习习惯。
-学会使用目标词汇和表达进行交流，如讨论不同的学习方法。
五、教学反思
在今天的教学中，我重点关注了一般现在时态在学习习惯描述中的应用以及与学习相关的词汇。通过观察学生的反应和参与度，我有以下几点思考：
首先，我发现学生在理解一般现在时态的概念上并没有太大困难，但在实际运用中，部分学生还是会出现时态混淆的情况。这说明在今后的教学中，我需要加大对学生时态运用的训练力度，特别是通过更多实例和情境模拟，帮助他们更好地掌握一般现在时的用法。
（2）词汇的灵活运用：学生可能难以将新学的词汇和表达灵活运用于不同情境中。
-难点举例：学生可能知道“take notes”的意思，但在实际对话中不知如何恰当使用。
（3）听力理解的深入：对于听力材料中的细节和言外之意，学生可能难以把握。
Unit1 How can we become good learners.Section A(3a
( )3.(2018·眉山)We find________impossible
for us________a foreign language well in a
short time. A．one；learn B．it；to learn C．that；to learn D．this；learning ( )4.—What a mess！The sharing bikes are
an English movie called... 一个叫作……的电影 fall in love with 爱上；喜欢上 begin to do sth. 开始干某事 begin的过去式为began body language 身势语；肢体语言 the secret to ... ……的秘诀
so...that... 如此……以至于…… be afraid to do sth. 害怕做某事 because of +n./n.短语 because +句子 hide behind 藏在……后面 hide的过去式为hid
初中英语人教版九年级
Unit1 How can we become good learners? Section A（3a~3b）
•学习目标
话题: 谈论如何学习
1.重点单词： expression,discover,secret,grammer,repeat, note,physics,chemistry,memorize,pattern 2.重点短语： because of,fall in love with,look up 3.重点句式：—How can I improve my pronunciation?
— One way is by listening to tapes. 4.语法：介词by引导方式状语
人教版英语九年级Unit 1 How can we become good learners Section A
初中英语学习材料madeofjingetiejiUnit 1 How can we become good learners Section A选词填空。
Listen to tapes , looking them up , reading aloud , made words cards , working with a groupquickly，slowly，secret，pronunciation，making1．You speak ________ so that everyone can hear you clearly．2．How ______he runs! I can’t catch up with him．3．I am afraid of speaking English in class because my ______ is poor．4．I study English by ______ word cards．5．It’s a ________ between us．Don’t tell anyone else6．I c an’t understand spoken English．一What about_____ to practice pronunciation．7．～How does your sister study for a test? 一She learns by_____ ．8．--I can’t get the pronunciation right．一Why don’t you ______ and read aloud．9．～Have you ever_______ to memorize the new words? 一Yes，I have made them．10．～What should I do if I don’t know how to spell the words?一How about ______ in a dictionary?用所给单词的适当形式填空。
Unit 1 How can we become good learners？Section B 1
Unit1 SectionB 1a-1e一、单项选择1．His trouble is that he always makes mistakes _____ spelling English words.A．on B．with C．in D．by2．-- My English is very weak. What shall I do?--- ________ join the English club? A．How about B．Why don`t C．Why not D．Let`s3．My brother keeps practicing ___________ English with his friends.A．to speak B．spoke C．speak D．speaking 4．— What’s the of the car at present?— It’s about 70 kilometers an hour.A．place B．speed C．price D．mark5．I really don't know _________ this question.A．which to do B．which to answer C．what to do D．how to answer 6．It’s very nice _________ you _________ me a lot.A．of; to help B．for; to help C．of; help D．for; help 7．He didn’t pay attention to _________ the news.A．listen to B．listening C．listen D．listening to 8．----Mr. Wu has recommended many books. Have you decided first?----Yes. The Little Prince.A．how to read B．which to read C．when to read D．where to read 9．Whether or not we can have a great success _________ our learning habits.A．plays a role in B．depends on C．pays attention to D．looks up to 10．— Will you go to visit the science museum tomorrow?— Sure! We will go _________ it rains.A．as long as B．as soon as C．even if D．so that二、完形填空Every student wants to study English well. There is no quick and easy way to learn English. But there is a simple and ___11___way. Speak English as much as you can. Try to talk in English ___12___your teacher and your classmates. Try to____13____to English on the radio and on TV.Don’t just read the____14____that you use in the class. Go to the____15____or a bookshop and read easy English books.Try to____16____something in English as much as you can, such as the things you did during the day.These____17____are not hard, but they are the work that you____18____do. If you do them, with the ___19___of your teacher, you will learn English___20___.11．A．dull B．all C．good D．close 12．A．with B．and C．of D．from 13．A．hear B．listen C．see D．look at 14．A．magazines B．textbooks C．newspapers D．picture-books 15．A．school gym B．playground C．library D．science labs 16．A．know B．find C．teach D．write 17．A．thing B．work C．job D．things 18．A．want B．like C．should D．shouldn’t 19．A．help B．present C．talk D．lessons 20．A．good B．well C．fine D．hardLast year I___21___ like my English class at all. The teacher spoke so quickly that I did not understand her most of the time. I was ___22___to answer the teacher's questions___23___my poor pronunciation. I just hid behind my textbook and never said __24__. Then one day I watched an English movie ___25___Toy Story, I fell in love with it at once. So I began to watch other English movies, ___26___, I realized I could get the meaningby___27___for just the key words. I discovered that listening to something interesting is the secret to language learning. I also learned some useful sentences like "It's a piece of cake" or "It serves you right". Ididn't understand them at first. But because I wanted to understand the story, I looked them __28__ in a dictionary. Little by little, I really enjoy my English class. And my English has improved a lot.21．A．don't B．didn't C．haven't D．hadn't 22．A．proud B．afraid C．happy D．excited 23．A．because of B．because C．since D．as 24．A．anything B．something C．nothing D．everything25．A．called B．call C．calling D．calls 26．A．as well B．too C．also D．neither 27．A．listen B．listened C．listening D．listens 28．A．up B．for C．at D．after三、补全对话7选5情景交际。
Unit1 How can we become good learners SectionA 3a-4c
( )5.I find ____very impartant to study English well?
A. its B. that C.this D.it
( ) 6.is really hardthem to climb Mount Huang.
be afraid to do sth.害怕/不敢做某事
That little girl is afraid to go out alone.那个小女孩不敢一个人出去。
afraid后可加不定式、of和动名词、that引导的从句
Our teacher is strict with us, but we are not afraid of her.
发现某人在干某事。Yesterday I found a boy playing in the park.
发现.......Gina findsthat she can not answer thequestion.
3.But I was afraid to ask questions because my pronunciation wasvery bad.
新目标九年级英语助学案
g
审核
英语组
课型
阅读课
课时
1
课题
Unit1 How can we become good learners?SectionA3a-4c
笔记栏
学习
目标
1掌握新单词expression, discover, secret ,look up,fall in love with,grammarrepeat ,note ,pal ,pattern,physics ,chemistry.
Unit1Howcan we become good learnersSectionB共33张
➢ 通过阅读课文及同学之间交流能反思自己 是否具备优秀学习者应具备的学习习惯和 方法，并学会使用词典。
Lead in How do you learn English?
Use it or lose it. Even if you learn something well, you will forget it unless you use it.
Alexander Graham Bell did not invent the telephone over night. He succeeded by trying many times and learning from
his mistakes.
Good learners will keep _p_ra_c_t_ic_i_ng_ what they have learned, and they are not afraid ofm_a_k_in_g__m_is_t_ak_e_s.
1. What is the passage about?
It's about how to be a sucessful learner. 2. What good habits do they have ?
(1) Creating an interesting in what they learn (2) Practicing and learning from mistakes (3) Developing their study skills (4) Asking questions
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
（确立合适的教学目标，要求明确、具体、细致）
认知目标：
1.学会运用how来询问做事方式
2.学会运用by+doing的结构表达做事方式。by介词，表示“通过……方法或途径”，译成“靠、通过”。by后面可以加名词或动名词短语。
3.动名词的构成：动词后加动名词doing，相当于名词。
技能目标：
1.教师引导学生回顾此前课本中所涉及的有关英语学习的一些良好方法，借此让学生对本单元进行一次全面浏览性复习
How can we learn English well?
by taking part in relevant activities in English
by reading English story book
by listening to tapes over and over again
by making word cards
You could try to improve your English by… This will help you to…
Step 4 Practice让学生练习写作。
Step 5写作展示及点评
Step 6 Then students complete the passage in Part 1 individually firstly, then check the answers together.
2.学生从罗列总结出的方法中适当选择，并按书本要求完成3a活动。
注意:教师尽量鼓励或要求学生结合自己英语学习的成功经验，独立填写表格内容，突出学习个性化。在此过程中，教师还应注意鼓励学生不断与周边同学进行交流，互相参考，补充完善自己所填内容，同时加强巡视指导。
3b Write a letter to your friend. Give him /her some advice about the best ways
2.学生总结出方法，完成写作练习。
情感目标：
通过对学习方法的学习，培养学生用正确而科学的方法做事的能力，引导学生学会能有意识地结合自身实际选择有效学习方式，以获取学业上的成功，明白“一份耕耘，一份收获”。
教学重点
If you do this,you will...
It is also a good idea to...because...
教学难点
If you do this,you will...
It is also a good idea to...because...
教学准备
PPT
课时安排
1
初 备 教 学 设 计
Step 1 Free talk
Talk about how we can learn English well with your partner.
Use the following expressions to help you:
There are three good ways to … I ቤተ መጻሕፍቲ ባይዱhink you should…
If you do this, you will… It is also a good idea to …because…
Best ways to learn
Reasons
Examples
1. Being interested in what you do
If you are interested in something, your brain will be more active and …
If you like music, you can learn English by listening to English songs.
by watching videos
Step 2 Presentation
1 3a Your friend wants to improve his/her English and asks you for help. What are
the three best ways to learn and why? Make some notes in the chart.
Taking part in relevant activities in English
practice oral English
by doing English game
Reading some books
improve your reading speed
by reading English story books
1)引导学生读出方框中的内容，确认他们能熟练认读这些词语。对于学习基础较弱县首只的学生，可要求他们在这些词语旁边注出汉语意思。
2)学生独立书本要求完成此项活动，教师巡视获取反馈。
3)学生相互结伴，核对修正自己的答案。
4)师生集体确认答案，然后集体诵读文段至熟练。
The answers: develop, take, notes, practice, remember, until, everything, prepare, worry about Then ask the students to read the short passage and discuss the problems they have.
to learn English. Use your notes in 3a.
3.教师让学生在完成表格填写后与周边同伴交换，双方开展校对式阅读( proofreading),就对方所写内容中自己看不明白或对语言正确性有疑虑的地方展开商讨交流，达到共同完善、提高的目的。
4.教师让学生先熟悉3b列出的常用表达和句式，然后按书本要求完成写作任务。若教学时间有限，可考虑将此活动布置为课外作业，学生课后完成，第二天课堂朗读交流或交教师批阅
集体备课（初备）教案
学 科
英语
年 级
九
初备时 间
年月日
单 元
U1
课 题
HHow can we become good learners?Section B2(Selfcheck)
主备人
备课意图
（分析本课在单元中的地位，设计备课的主要目的）
本节内容是本单元的第六课时，即是对学生前五课时的学习中涉及到的基础知识的复习巩固，又需要围绕“如何学习英语”的核心话题运用by+ving结构培养学生的写作能力。通过对本节课活动设计及实际教学活动，达到对单元知识进行巩固提升熟练运用的目的。