Unit 6 At one with nature 导学案-2024-2025学年高一英语外研版（2019）必修第一册

学科教师辅导讲义 授课日期及时段 教学目标 新必修第一册Unit 6 重点难点 “介词＋关系代词”引导的定语从句 教学内容 ( 课堂导入 ) Ⅰ.匹配下列单词的词性及汉语意思 (　　)1.wrap　　　　 A．v.阻挡，防止 (　　)2.sheet B．adj.重要的，影响深远的 (　　)3.dynasty C．v.包，裹 (　　)4.completion D．n.传统 (　　)5.region E．n.(一)大层(覆盖物) (　　)6.prevent F．n.完成，结束 (　　)7.significant G．n.融洽，和谐 (　　)8.harmony H．n.地区，区域 (　　)9.tradition I．v.吸引，引起……的兴趣 (　　)10.attract J．n.朝代 Ⅱ.选择下列句中词组的汉语意思 A．再一次　　　　 B．费力去做…… C．大量的 D．几百年 E．被覆盖在……里 F．目光所及 G．……的家园 H．包裹在……里 (　　)1.It was dark and shiny, and was wrapped in silver paper. (　　)2.His children's clothes were covered in dirt. (　　)3.The wetlands are home to a large variety of wildlife. (　　)4.Bankers and clock­makers have coexisted in the city for hundreds of years. (　　)5.People often wonder why historians go to so much trouble to protect. (　　)6.As far as the eye can see under your command. (　　)7.She is in the fortunate position of having plenty of choices. (　　)8.America is once again being seen as a strong, can­do nation. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ( 知识讲解 ) Section Ⅱ 必备句式 背教材原句 记句式结构 仿写促落实 1.Imagine mountains wrapped in silver water，shining in the spring sun. 想象一下，群山被银色的水包裹着，在旋转的太阳下闪闪发光。 过去分词短语作 补语 The government asked him to get the dangerous building pulled down. 政府要求他把他的危险建筑推倒。 2.These terraces were built by the local Zhuang and Yao people, to whom Guangxi is home. 这些梯田是当地的壮族和瑶族人建造的，对他们来说广西就是他们的家。 介词＋whom引导的定语从句 The girl with whom I shook hands at the school gate is the best singer in our school. 我在校门口和她握手的那个女孩是我们学校的最佳歌手。 3.Reaching as far as the eye can see，these terraces cover tall mountains, often from the bottom to the very top. 目光所及都是梯田，它们覆盖座座高山，通常从山脚到山顶。 现在分词短语作 状语 Hearing the news of the team being defeated，she burst into tears. 听说了小组失败的消息，她放声大哭。 4.But perhaps what is most significant is the way in which people have worked in harmony with nature to make these terraces and grow rice. 但或许最重要的是人们与自然和谐相处的方式，目的就是为了建造梯田，种植水稻。 what引导的主语 从句 What they really need is enough money for them to establish the fund. 他们真正需要的是足够的钱，让他们来建立基金。 5.During the rainy season，it is along these waterways that rainwater moves down the mountains and into the terraces. 在雨季，雨水正是沿着水道从山上往下流到梯田里。 强调句型 It is from the sun that we get light and heat. 我们是从太阳那里得到了光和热。 重点词汇 cover vt.覆盖；行走(路程)；采访；占用(一段时间或空间)；包含；足以支付 n．封面(底)；盖子 (教材P62)During autumn, these same mountains are flash gold, and in winter they are covered in sheets of white frost. 秋天里，同样的山成了闪闪亮的金子并且冬天里它们被一层层的白霜覆盖。 　写出下列句中cover的词性及含义 ①The books on the desk，whose covers are shiny，are prizes for us._______ ②—How much do you know about the Youth Olympic Games to be held in Nanjing? —Well，the media have covered it in a variety of forms._______ ③During the summer camp，the children will be instructed by the teacher to cover 30 miles a day._______ ④As the price is rising，$100 a month can hardly cover the cost of his life in such a big city._______ ⑤Norton Sound was covered with ice, which could sometimes break up without warning._______ cover...with...　　　　　 用……盖住…… be covered by/with 被/由……覆盖 cover up 遮盖；隐瞒 cover an area of... 占地面积为…… go to so much trouble to do费大力气去做某事；费事去做某事 (教材P62)So why did these people go to so much trouble to turn entire mountains into terraces? 那么为什么那些人费那么大力气把整座整座的山变成梯田呢？ take the trouble to do sth.　 费力做某事，不辞劳苦做某事 bother to do something 费力去做某事 have trouble (in) doing sth. 做什么事有麻烦/困难 in trouble 处于困境之中 make trouble 制造麻烦 get into trouble 陷入麻烦 ①Please don't go to so much trouble to help me，or I'll feel I'm being treated as a stranger. 你对我这样客气，倒有点见外了。 ②The couple laughed off rumors that their marriage was in trouble. 夫妻两人对他们婚姻出现问题的谣言一笑置之。 ③She did not bother _______(keep) up with the news. 她不愿花时间去了解最新消息。 ④I never have trouble _______(sleep) in a strange place. 我从来不择席。 [明辨异同]　effort，trouble，pains，struggle effort 通常指完成某特定任务所需付出的或大或小的努力，可指一次的努力， 也可指坚持不懈的努力。 trouble/pains 均侧重在面临困难或阻力时所作的努力，但强调在努力时的细心和谨慎， 相比之下，pains更适合表示尽力的努力。 struggle 指为克服困难或阻力所作的努力，也指因决心、意志或干劲而产生的极大努力。 prevent...from...阻挡/防止……做…… (教材P63)The flat terraces catch the rainwater and prevent the soil from being washed away. 平坦的梯田能留住雨水，防止土壤被冲走。 prevent sb.from sth.　 阻止某人免于…… stop sb.from doing sth. 阻止某人做…… keep sb.from doing sth. 阻止某人做…… discourage sb.from doing sth. 阻止某人做…… ①To prevent from fire or shock, please don't use a damaged cord. 为防火灾或电击， 请不要用已损坏的电源线。 ②Who prevents the plans from ______________(carry)out? 谁阻止了这个计划的实施？ ③He ____________(prevent)by law from holding a licence. 法律不准他持有执照。 ④Further treatment will prevent cancer ____________ developing. 进一步的治疗将阻止癌症恶化。 harmony n．融洽；和谐 (教材P63)But perhaps what is most significant is the way in which people have worked in harmony with nature to make these terraces and grow rice. 但或许最重要的是人们与自然和谐相处的方式，目的就是为了建造梯田，种植水稻。 (1)in harmony with sb./sth. 与……协调；与……相配 out of harmony with sb./sth. 与……不协调 live/work in harmony 生活/工作得很融洽 (2)harmonious adj. 和谐的，协调的，和睦的 ①The “Chinese Dream” is a dream to improve people's well­being and a dream of harmony，peace and development. “中国梦”是一个提升人民幸福感的梦，也是一个和谐、和平以及发展的梦。 ②When children grow up, their ideas will be out of harmony with their parents'. 孩子们长大后，他们的想法会和父母的想法有出入。 ③Only when we realize the importance of helping each other can we be devoted to building a ____________(harmony) society. 只有当我们意识到互助的重要性，我们才能致力于建设和谐社会。 ④In addition, every student can be in harmony with foreign friends, which makes it easy for you to get along with them.另外，每个学生都和外国友人和睦相处，这样也会让你和他们能相处融洽。 design n．设计，图案 vt.设计；计划，谋划；构思 (教材P63)The terraces are cleverly designed，with hundreds of waterways that connect with each other. 梯田的设计精巧，其间由几百条彼此相连的水道。 (1)design sth.for... 为某目的或用途而制造或计划…… be designed for.../to do sth. 目的是…… (2)by design(＝on purpose) 故意地，蓄意地 by accident/by chance 偶然地 ①They asked me to design a poster for the party which will be held on New Year's Day in 2020. 他们请我为2020年元旦将要举行的晚会设计一张海报。 ②This program designed to help jobless people just didn't work out as planned. 这个旨在帮助失业人员的项目没有按计划那样奏效。 ③The project____________(design) for the disabled is very popular with them. 专门为残疾人设计的项目很受他们欢迎。 ④Do you think the building was burnt down by accident or by design? 你认为这座大楼是偶然起火还是有人蓄意纵火？ 重点句式 (教材P62)Reaching as far as the eye can see，these terraces cover tall mountains, often from the bottom to the very top. 目光所及都是梯田，它们覆盖座座高山，通常从山脚到山顶。 【要点提炼】　 (1)Reaching as far as the eye can see是现在分词短语作状语。 现在分词短语作状语时，可以表时间、原因、结果、条件、让步、行为方式、伴随状况等。为了强调，还可与while，when，once，if，unless等连词连用。 ①Turning to the left，you will find the school. 向左拐，你就会发现那所学校。 ②Knowing where I live，he never comes to see me. 尽管知道我住哪儿，但他从不来看我。 ③He turned off the lamp，____________(see)nothing. 他熄了灯，结果什么也看不见了。 ④While walking the dog，you were careless and it got loose and was hit by a car. 遛狗时，你不小心把狗松开了，结果狗被一辆汽车撞了。 (2)as far as作从属连词，意为“就……来说，在……范围内”，强调程度或范围，常与know, see, concern等动词连用。 as far as I'm concerned　 据我所知 as far as (it) is known 众所周知 as far as I can feel 就我的感觉 as far as I know 据我所知 ⑤As far as the eye can see，the waves are to be seen rolling in all directions. 极目望去，到处浪涛滚滚。 ⑥As far as I'm concerned，not only does outdoor exercise get us close to nature but also give us relaxation from heavy schoolwork. 就我个人而言，户外运动不仅使我们接近大自然，而且使我们从沉重的学习任务中摆脱出来得以休息。 ⑦As far as I know，compared with other countries, Chinese students spend much more time studying. 据我所知，与其他国家相比较，中国学生花费更多的时间来学习。 ⑧As far as English is concerned(concern)，it is not so difficult as you might think. 就英语而言，它并不像你所认为的那样难。 长难句式 1．(教材P62)Building the terraces therefore meant that they could increase the areas in which they could grow rice. 【分析】　该句是主从复合句。主句是____________结构，其中building the terraces是主语部分。宾语是由____________引导的宾语从句，其中的in which they could grow rice是____________从句，修饰前面的the areas。 【翻译】　因此，建造梯田就意味着他们能够增加种植水稻的面积。 2．(教材P63)This knowledge is passed down through families, which means that new generations continue to use ancient methods of agriculture to maintain the terraces. 【分析】　该句是主从复合句。主句是被动语态。which引导的是____________从句，解释说明前面的主句。从句是主谓宾结构，宾语是____________引导的____________从句。 翻译】　这样的知识通过家庭代代相传，这就意味着年轻一代在延续着维护梯田的古老农耕方法。 Section Ⅲ 重点词汇 population n．人口；数量；全体居民； 特定(生物)种群；(物)布居； (教材P65)The population of the Zhuang people is the largest of the ethnic groups in China. 壮族人口是中国少数民族中最多的。 (1)有……人口 (2)某国/某地的人口the population of＋地点 (3)询问某国某地有多少人口 (4)整体人口(the population of...)作主语时，谓语动词用单数；部分人口(表示“人口的百分之几、几分之几”)作主语时，谓语动词用复数。 ①Japan has a population of nearly 130 million. 日本有近1.3亿人口。 ②The population of Jiangsu ____________(grow)to more than twice what it was in 1949. 现在江苏的人口已经比1949年增长了两倍多。 ③About seventy percent of the population in China ____________(be) farmers. 中国70%的人口是农民。 ④Do you know how large the population of your city is? 你知道你们市的人口是多少吗？ [温馨提示]　population可用large或small来修饰。 divide into把……(划)分成…… The Chinese lunar calendar divides the year into 24 solar terms. 中国的农历把一年分为24个节气。 divide...into...　　　 把……分成 divide...among/between 在……之间分配…… divide...in half/two/halves 把……分成两部分 ①The man divided the food into halves and carefully placed one before his wife. 这个男人把食物分成两份并小心翼翼地把一份放在妻子面前。 ②After his death his property____________(divide)among his children. 他死后，他的财产就由他的孩子们平分。 ③As is known to us, a year is divided into four seasons.众所周知，一年分为四个季节。 (1)add to　　　　　　 增加；增添 (2)add up 把……加起来 (3)add up to 合计达 (4)in addition 另外 (5)in addition to 除……之外 [明辨异同]　divide/separate divide 常指把某个整体划分为若干部分，常与into搭配 separate 表示“将……与……分开”，指把原来连在一起或靠近的个体分隔开来，常与from搭配 located adj.坐落(某处)的；位于(某处)的 (教材P66)Located in the Coral Sea, the Great Barrier Reef is the biggest structure made by living organisms.大堡礁坐落于珊瑚海，是由活着的有机体组成的最大的结构。 be located on/in/at... 位于……的；坐落在……的 locate v. 位于； 说出来源； 查找……的地 点； 确定……的位置 location n. 位置，场所； 定位； 外景(拍摄地) ①That is a small town located just(to the)south of Cleveland. 那是一个地处克利夫兰以南的小城。 ②Try to ____________(located)exactly where the smells are entering the room. 找找看气味具体是从什么地方散入房间的。 ③The ____________(located)has been changed at the last minute.在最后一刻改变了地点。 定语从句(3)——“介词＋关系代词”引导的定语从句 语 境 自 主 领 悟 先观察原句 后自主感悟 阅读下列句子，并体会黑体部分的用法 1.He likes the birthday gifts that his friends gave him. 2.The girl who you have just seen is very good at English. 3.I don't know the teacher whom I met in the computer room. 4.Is this the play which you were talking about just now? 5.Daniel is the person whom I want to make friends with. 6.The subject which Eric is interested in is Physics. 7.This is the house(which/that) I used to live in. 8.This is the house in which I used to live. 9.We'll go to hear the famous singer(whom/that/who)we have often talked about. 10.We'll go to hear the famous singer about whom we have often talked. 1.例句1、例句2和例句3中关系词在从句中作________的宾语。 2.例句4、例句5和例句6关系词在从句中作介词的宾语。 3.例句7和例句9中，关系代词在定语从句中作介词宾语时。代指人时从句常可用________引导，且可以省略掉。代指物时从句常可用________引导，且可以省略掉。 4.例句8和例句10中，若介词放在关系代词前， 关系代词指人时常用________，不可用________。指物时用________，不能用that并且都不可以省略。 “介词＋关系代词”引导的定语从句 此类从句是定语从句中一种介词前置句型，介词与关系代词之间存在一种介宾关系。 当关系代词在定语从句中作介词宾语时，把介词置于关系代词前， 即演变出“介词＋关系代词”句型。 一、基本构成 1．“介词＋关系代词”结构引导的定语从句中，关系代词只能用 which(指物)或 whom(指人)，即： 介词＋which/whom。 2．在限制性定语从句中，当介词置于定语从句的谓语动词之后时，可用 that/which(指物); that/who/whom(指人)作介词的宾语，且此处关系代词可以省略，特别是在口语中。如： The man (who/whom/that)you spoke to is a teacher. 你同他说话的那个人是一位老师。 The city(which/that)she lives in is far away. 她居住的城市很遥远。 [即时演练1]　判断正误 1．The man with whom you talked is my friend.(　　) 2．The man(who/that) you talked with is my friend.(　　) 3．The man with who/that you talked is my friend.(　　) 4．The plane in which we flew to Canada is very comfortable.(　　) 5．The plane in that we flew to Canada is very comfortable.(　　) 二、关系副词 when，where，why 可用“介词＋which”来代替。关系副词实际上是介词＋先行词。其中 when＝表时间的介词(如：in，at，during 等)＋which；where＝表地点的介词(如：in，at，on，under 等)＋which；why＝表原因的介词(如：for)＋which (1)当先行词表示时间，定语从句中缺少时间状语时，通常用关系副词 when 引导，此时也可选用表 示时间的介词＋which 来代替关系副词 when。 I still remember the day when I came here.( on the day ＝when) 我依然记得我来这里的那一天。 (2)当先行词表示地点，定语从句中缺少地点状语时，通常用关系副词 where 引导，此时也可选用表 示地点的介词＋which 来代替关系副词 where。 This is the house where I lived last year.( in the house＝ where) 这就是我去年住的那所房子。 (3)当先行词为 reason，定语从句中缺少表示原因状语时，通常用关系副词 why 引导，此时也可以用 for which 来代替关系副词 why。 There are many reasons why people like travelling.(for the reasons ＝why) 人们喜欢旅游有很多原因。 三、关系代词前介词选择三原则：一看先行词，二看动词，三看意义(重中之重) 1．一看先行词，即根据定语从句中介词与先行词的搭配关系选择。 I never forget the day on which I came to this school. 我永远忘不了我来这所学校的那一天。 2．二看动词，即根据定语从句中谓语动词与介词的搭配关系选择。 This is the iPad on which I spent 3，000 yuan. 这就是我花了三千元买的iPad. 3．三看意义，即根据定语从句的意义来确定介词。 This is my pair of glasses，without which I cannot see clearly. 这就是我的那副眼镜，没有它我看不清楚。 [即时演练2]　用“介词＋关系代词”的形式填空 1．Do you like the book she learned a lot? 2．He paid the boy $10 for washing ten windows, most hadn't been cleaned for at least a year. 3．The tower people can have a good view is on the hill. Section Ⅳ 必备句式 背教材原句 记句式结构 仿写促落实 1.Today, millions of Brits like to say that they have “green fingers”，with around half the population spending most of their free time gardening. 如今，几百万的英国人会说他们是园艺高手，大约有一半的人口都在用业余时间搞园艺。 with＋宾语＋doing He went home alone, with cold wind blowing outside. 外面刮着冰冷的寒风，他独自回家了。 2.Where you tend a rose...a thistle cannot grow. 你种玫瑰的地方，就不会长杂草。 where引导的地点状语从句 Where there is a will，there is a way. 有志者，事竟成。 重点词汇 limited adj.有限的 (教材P70)But in cities，limited space has led to people looking for new solutions. 但是在城市里，有限的空间使得人们都在寻找新的解决方案。 (1)limit n．　　　　　　　 限度；限制；范围；界限 within limits 适度地；有限度地 without limit 无限地；无限制地 (2)limit vt. 限制；限定 limit sb./sth.to sth. 把……限制在……之内 (3)limitless adj. 无限的 ①I'm willing to help，within limits. 我愿意帮忙，可有一定的限度。 ②Families are limited to four free tickets each. 每户限发四张免费票。 ③This course ________(limit) to 12 people and costs ￡50.该课程只招收12人，学费为50英镑。 ④We must limit the speech to 15 minutes. 我们必须把演讲限制在15分钟之内。 重点词汇 (教材P68)Today, millions of Brits like to say that they have “green fingers”，with around half the population spending most of their free time gardening． 如今，几百万的英国人会说他们是园艺高手，大约有一半的人口都在用业余时间搞园艺。 【要点提炼】　 本句中with around half the population spending是“with ＋ 宾语＋宾语补足语”结构，属with复合结构。因宾语around half the population和宾语补足语之间是逻辑上的主谓关系，所以宾语补足语用v.­ing形式，表示主动。 (1)常见的with复合结构： with＋宾语＋形容词/副词/介词短语 with＋宾语＋doing(表主动、进行) with＋宾语＋done(表被动、完成) with＋宾语＋to do(表未做) (2)with复合结构 常作原因、条件、时间、方式或伴随状语，也可作后置定语。 ①I couldn't put into my study with the children making noise outside. 孩子们在外面制造噪音，我不能投入进去学习。 ②He is used to sleeping with the window open at night even in winter. 即使在冬天的夜晚他也习惯开着窗睡觉。 ③With a lot of work to do(do)，we cannot go out to play basketball. 有许多工作要做，我们不能出去打篮球了。 ④With their work finished(finish)，they went to see the movie Wandering Earth together. 完成工作后，他们结伴去看电影《流浪地球》了。 长难句 (教材P69)And if you're in any doubt about this, take a moment to reflect on this line from The Secret Garden：Where you tend a rose...a thistle cannot grow. 【分析】　该句是一个主从复合句。if引导的是________从句，主句是take开头的________句。引用的句子也是个主从复合句。where引导的是________从句。 【翻译】　如果你对此有所怀疑，那就花点时间思考一下《秘密花园》中的这句话吧：你种玫瑰的地方，就不会长杂草。 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ( 练习巩固 ) Ⅰ.单句语法填空 1．He is a great ___________(admire)of Picasso's early paintings. 2．—We need to keep working and find a _________(solve) as soon as possible to the problem. —I couldn't agree more. 3．It's _________(tradition)in China to eat moon cakes on the Mid­Autumn Festival. 4．They asked me _________(design)a poster for the campaign. 5．We ____________(complete) all the tasks before he comes back. 6．How can we prevent the clean water __________ being polluted by the neighboring factories? 7．__________(attract)by the beautiful scene here, he decided to stay here for long. 8．Warwick is home ____ some 550 international students. 9．Many foreigners go to a lot of trouble _________(get) a Residence Permit, the Chinese green card. 10．What first __________(attract) me to her was her sense of humour. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ( 家庭作业 ) Ⅰ.阅读理解 A For the last couple of weeks，I had been stuck in front of my computer working on a project that was very important to me.My every waking hour was consumed by the project and although I imagined that I would feel happy after completing parts of the project，I was confused to find that instead, I was feeling rather depressed.I tried a range of methods to help cheer myself up.I had a relaxing bath, cooked a delicious meal to enjoy with my family and even watched a light­hearted movie，but to no avail．It was only when I turned to meditation (沉思) for a solution that the answer came to me：turn to nature! The very next day, I grabbed my camera and a bottle of water and set off to spend a few hours walking in a nature reserve，even though it was raining heavily.Within a couple of minutes I felt alive again.To be honest, I felt like a young school girl again and had to stop myself from hopping along the path singing.I'm singing in the rain，a song I used to sing when I was a child.I think as adults we often try too hard to control our inner children and as a result we restrain (限制) our own spirits，which only leads to depression and stress. Interestingly，it has been shown that people who spend 40 minutes walking in a nature reserve have a drop in their blood pressure levels, but this does not happen when they spend a similar amount of time walking in a busy city centre. If you feel a little low in spirit and know that you have spent too much time indoors，relax completely，remove your shoes and let your inner child come out and play. 1．The author felt depressed because she ． A．couldn't consume her waking hour B．had not seen a film for a long time C．had not finished her work on time D．had worked on an important project for too long 2．The underlined part “to no avail” in Paragraph 1 probably means“ ”． A．unsuccessful　　 B．unrelated C．uninteresting D．unexpected 3．In the author's opinion， ． A．a bath can make people relaxed B．depression is usually caused by hard work C．walking in a busy city centre harms people's health D．adults should express their inner feelings freely B On a hill 600 feet above the surrounding land, we watch the lines of rain move across the scene, the moon rise over the hills, and the stars appear in the sky.The views invite a long look from a comfortable chair in front of the wooden house. Every window in our wooden house has a view，and the forest and lakes seldom look the same as the hour before.Each look reminds us where we are. There is space for our three boys to play outside，to shoot arrows，collect tree seeds，build earth houses and climb trees. Our kids have learned the names of the trees，and with the names have come familiarity and appreciation.As they tell all who show even a passing interest, maple(枫树) makes the best fighting sticks and white pines are the best climbing trees. The air is clean and fresh.The water from the well has a pleasant taste, and it is perhaps the healthiest water our kids will ever drink.Though they have one glass a day of juice and the rest is water, they never say anything against that. The seasons change just outside the door．We watch the maples turn every shade of yellow and red in the fall and note the poplars(杨树) putting out the first green leaves of spring.The rainbow smelt fills the local steam as the ice gradually disappears, and the wood frogs start to sing in pools after being frozen for the winter.A family of birds rules our skies and flies over the lake. 4．What can be learned from Paragraph 2? A．The scenes are colorful and changeable. B．There are many windows in the wooden house. C．The views remind us that we are in a wooden house. D．The lakes outside the windows are quite different in color. 5．By mentioning the names of the trees，the author aims to show that ． A．the kids like playing in trees B．the kids are very familiar with trees C．the kids have learned much knowledge D．the kids find trees useful learning tools 6．What does the underlined sentence in the last paragraph mean? A．The change of seasons is easily felt. B．The seasons make the scenes change. C．The weather often changes in the forest. D．The door is a good position to enjoy changing seasons. 7．What is the main purpose of the author writing the text? A．To describe the beauty of the scene around the house. B．To introduce her children's happy life in the forest. C．To show that living in the forest is healthful. D．To share the joy of living in the nature. 1 学科网（北京）股份有限公司 $$