最新大學(xué)英語四級(jí)考試閱讀材料每日一練

1、大學(xué)英語四級(jí)考試閱讀材料每日一練（08180904）大學(xué)英語四級(jí)考試閱讀材料每日一練（） Passage 1Oceanography has been defined as “The application of all sciences to the study of the sea”.Before the nineteenth century ,scientists with an interest in the sea were few and far between.Certainly Newton considered some theoretical aspects of it i

2、n his writings ,but he was reluctant to go to sea to further his work.For most people the sea was remote, and with the exception of early intercontinental travelers or others who earned a living from the sea ,there was little reason to ask many questions about it ,let alone to ask what lay beneath t

3、he surface. The first time that the question ”what is at the bottom of the oceans? ”had to be answered with any commercial consequence was when the laying of a telegraph cable from Europe to America was proposed. The engineers had to know the depth profile of the route to estimate the length of cabl

4、e that had to be manufactured.It was to Maury of the US Navy that the Atlantic Telegraph Company turned, in 1853, for information on this matter. In the 1840s, Maury had been responsible for encouraging voyages during which soundings were taken to investigate the depths of the North Atlantic and Pac

5、ific Oceans. Later, some of his findings aroused much popular interest in his book The Physical Geography of the Sea.The cable was laid, but not until 1866 was the connection made permanent and reliable. At the early attempts, the cable failed and when it was taken out for repairs it was found to be

6、 covered in living growths, a fact which defied contemporary scientific opinion that there was no life in the deeper parts of the sea.Within a few years oceanography was under way. In 1872 Thomson led a scientific expedition, which lasted four years and brought home thousands of samples from the sea

7、. Their classification and analysis occupied scientists for years and led to a five-volume report, the last volume being published in 1895. 1、 The proposal to lay a telegraph cable from Europe to America made oceanographic studies take on _C_.A) an academic aspect B) a military aspect C) a busi

8、ness aspect D) an international aspect2、 It was _D_that asked Maury for help in oceanographic studies.A) the American Navy B) some early intercontinental travelers C) those who earned a living from the sea D) the company which proposed to lay an undersea cable3、 The aim of the voyages Maury was resp

9、onsible for in the 1840 was_D_A) to make some sounding experiments in the oceans B) to collect sample of sea plants and animalsC) to estimate the length of cable that was neededD) to measure the depths of the two oceans4、”Defied” in the 5th paragraph probably means “_C_”A) doubted B) gave proof to C

10、) challenged D) agreed to 5、 This passage is mainly about_A_A) the beginnings of oceanography B) the laying of the first undersea cableB) the investigation of ocean depths D) the early intercontinental communications  Passage 1 (The original text translating )海洋學(xué)的定義是“慶用所有的科學(xué)來研究海洋”世紀(jì)以前，極少有科

11、學(xué)家對(duì)研究海洋感興趣，當(dāng)然，牛頓在他的作品中對(duì)海洋做了一些理論方面的探討，但他并不情愿自己去海邊作進(jìn)一步的研究。對(duì)大多數(shù)人來說，海洋是遙遠(yuǎn)的，除了早期穿越洲際的旅行家們以及依靠海洋維持生計(jì)的人，幾乎找不出理由要提出關(guān)于海洋的問題，更不會(huì)問海洋表面下還有些什么東西。人們第一次必須回答“海洋底部是什么？”（）這個(gè)問題是有商業(yè)上的后果的，當(dāng)時(shí)有人提議要鋪設(shè)一條從歐洲到美洲的電報(bào)纜線。工程師們必須了解路線的縱深起伏形狀，才可以估計(jì)需要制造多長(zhǎng)的電纜。（）由于美國(guó)海軍的莫里（Maury），大西洋電報(bào)公司才在年得到了這方面的信息。世紀(jì)年代，（）莫里負(fù)責(zé)推動(dòng)進(jìn)行測(cè)探工作的海上航行，以此來調(diào)查北大西洋與太平洋

12、的深度。此后，他出了一本叫做海洋的自然地貌的書，在這本書里他提到的一些發(fā)現(xiàn)激起了人們很大的興趣。人們鋪設(shè)了電纜，但直到年，才有了固定而且可靠的連接。在早期的努力中，電纜壞了，而當(dāng)它被拉出來維修時(shí)，人們發(fā)現(xiàn)其表面覆蓋著（）活的生物。這一事實(shí)挑戰(zhàn)了當(dāng)時(shí)的一種科學(xué)觀點(diǎn)，即海洋較深層是不存在生命的。海洋學(xué)在此后幾年內(nèi)發(fā)展起來。年，湯姆森（Thomson），帶頭進(jìn)行了一項(xiàng)科學(xué)考察，歷時(shí)年，從海洋帶回了數(shù)以千計(jì)的標(biāo)本。科學(xué)家們花了數(shù)年時(shí)間將它們分類并進(jìn)行分析，寫出了一個(gè)長(zhǎng)達(dá)五卷的報(bào)告，其中最后一卷于年出版。  、 從歐洲到美洲鋪設(shè)電報(bào)纜線的提議使得海洋學(xué)研究是從_出發(fā)的）學(xué)術(shù)角度）軍事

13、角度）商業(yè)角度）國(guó)際角度、 向莫里要求得到海洋學(xué)研究方面幫助的是_）美國(guó)海軍）一些早期的穿越大洲的旅行家）依靠海洋維持生計(jì)的人）提議鋪設(shè)一條海底電纜的公司、 世紀(jì)年代，莫里負(fù)責(zé)的海上航行的目的是要_）在海上進(jìn)行測(cè)探實(shí)驗(yàn)）收集海洋動(dòng)植物的標(biāo)本）估測(cè)所需電纜的長(zhǎng)度）測(cè)量?jī)蓚€(gè)海洋的深度、 第五段的“ field ”一詞可能的意思是_）置疑）證明）挑戰(zhàn)）同意、 這一段文章主要是關(guān)于_）海洋學(xué)的起步）第一條海底電纜的鋪設(shè)）對(duì)海洋深度的研究）早期的洲際交流   大學(xué)英語四級(jí)考試閱讀材料每日一練（） Passage 2 Normally a student must atten

14、d a certain number of courses in order to graduate, and each course which he attends gives him a credit which he may count towards a degree, In many American universities the total work for a degree consists of thirty-six courses each lasting for one semester. A typical course consists of three clas

15、ses per week for fifteen weeks; while attending a university a student will probably attend four or five courses during each semester. Normally a student. Would expect to take four years attending two semesters each year. It is possible to spread the period of work for the degree over a longer perio

16、d. It is also possible for a student to move between one university and another during his degree course, though this is not in fact done as a regular practice.For very course that the follows a student is given a grade, which is recorded, and the record is available for the student to show to prosp

17、ective employers. All this imposes a constant pressure and strain of work , but in spite of this some students still find time for great activity in student affairs. Elections to positions in student organizations arouse much enthusiasm. The effective work of maintaining discipline is usually perfor

18、med by students who advise the academic authorities. Any student who is thought to have broken the rules, for example, by cheating his to appear before a student court. With the enormous numbers of students, the operation of the system does involve a certain amount of activity. A student who has hel

19、d one of these positions of authority is much respected and it will be of benefit to him later in his career. 6、Normally a student would at least attend _B_classes each week.A） 36 B） 12 C） 20 D） 157、According to the first paragraph an American student is allowed_B_A） to live in a different univ

20、ersityB） to take a particular course in a different universityC） to live a home and drive to classesD） to get two degrees from two different universities8、America university students are usually under pressure of work because_A_A） their academic performance will affect their future careersB） they ar

21、e heavily involved in student affairsC） they have to observe university disciplineD） they want to run for positions of authority9、Some students are enthusiastic for positions in student organizations probably because_C_A） they hate the constant pressure and strain of their study B） they will then be

22、 able to stay longer in the universityC） such positions help them get better jobsD） such positions are usually well paid10、The student organizations seem to be effective in _B_A） dealing with the academic affairs of the universityB） ensuring that the students observe university regulationsC） evaluat

23、ing students performance by bringing them before a courtD） keeping up the students enthusiasm for social activities Passage 2 通常，一名學(xué)生必須參加一定數(shù)量的課程學(xué)習(xí)才可以畢業(yè)，他上的每一門課都會(huì)得到學(xué)分，這些學(xué)分累加起來，才能拿到學(xué)位。在許多美國(guó)大學(xué)里，要拿到學(xué)位就得上門課，每門課要上一個(gè)學(xué)期。（）一門典型的課程是每個(gè)星期上節(jié)課，共上個(gè)星期；而一名大學(xué)生可能（）每學(xué)期要學(xué)習(xí)到門課程。通常每個(gè)學(xué)生都應(yīng)該上年學(xué)，每年兩個(gè)學(xué)期。有可能要花超過年的時(shí)間才能

24、拿到學(xué)位，（）也有可能一個(gè)學(xué)生在攻讀學(xué)位時(shí)在兩所不同的大學(xué)上課，然而，這實(shí)際上并不常見。學(xué)生上的每一門課都會(huì)有一個(gè)分?jǐn)?shù)，分?jǐn)?shù)是有記錄的，（）學(xué)生可以把他的分?jǐn)?shù)記錄給未來的雇主看。這些為學(xué)生施加了學(xué)習(xí)上長(zhǎng)期的壓力和負(fù)擔(dān)。但盡管如此，有些學(xué)生還是能擠出時(shí)間來積極參與學(xué)生活動(dòng)。競(jìng)選學(xué)生組織中的職位能夠激發(fā)很大的熱情。（）遵守紀(jì)律的有效承諾通常是由向校方提議的學(xué)生們來執(zhí)行的。任何被認(rèn)為違反了規(guī)定的學(xué)生，比如說，考試作弊的學(xué)生，必須在學(xué)生法庭上受審。學(xué)生數(shù)目眾多，則這一體系在動(dòng)作時(shí)就會(huì)涉及到為數(shù)不少的學(xué)生活動(dòng)。（）在其中擔(dān)任過領(lǐng)導(dǎo)職位的學(xué)生就會(huì)很受人尊敬，對(duì)他將來的事業(yè)也很有利。 、通常一名學(xué)

25、生每星期要上至少_節(jié)課。A）B）C）D）、根據(jù)本文第一段，美國(guó)學(xué)生可以_A）住在不同的大學(xué)里B）在另一所大學(xué)上某一門特定的課程C）住在家里，開車去上課D）從兩所大學(xué)得到兩個(gè)學(xué)位、美國(guó)大學(xué)生通常都會(huì)感到學(xué)習(xí)的壓力，因?yàn)開A） 他們?cè)趯W(xué)術(shù)上的表現(xiàn)會(huì)影響他們未來的工作）他們過多地參與學(xué)生活動(dòng)B） 他們必須遵守學(xué)校紀(jì)律）他們想爭(zhēng)取領(lǐng)導(dǎo)職位、有些學(xué)生熱衷于學(xué)生組織中的職位可能是因?yàn)開A）他們痛恨學(xué)習(xí)上長(zhǎng)期的壓力和負(fù)擔(dān)B）這樣他們要吧在學(xué)校待得長(zhǎng)一些C）這種職位有助于他們找到較好的工作D）這種職位通常報(bào)酬優(yōu)厚、學(xué)生組織似乎在_方面卓有成效。A）處理學(xué)校的學(xué)術(shù)活動(dòng)B）確保學(xué)生遵守校紀(jì)C）通過學(xué)生法庭的審判衡

26、量學(xué)生們的表現(xiàn)D）保持學(xué)生們對(duì)社會(huì)活動(dòng)的熱情    大學(xué)英語四級(jí)閱讀材料每日一練（） Passage 3Do you find getting up in the morning so difficult that its painful? This might be called laziness, but Dr.Kleitman has a new explanation. He has proved that everyone has a daily energy cycle.During the hours when you labour thr

27、ough your work you may say that youre “hot”. Thats true. The time of day when you feel most energetic is when your cycle of body temperature is at its peak. For some people the peak comes during the forenoon. For others it comes in the afternoon or evening. No one has discovered why this is so, but

28、it leads to such familiar monologues as: “Get up, John! Youll be late for work again!” The possible explanation to the trouble is that John is at his temperature-and-energy peak in the evening. Much family quarrelling ends when husbands and wives realize what these energy cycles mean, and which cycl

29、e each member of the family has.You cant change your energy cycle, but you can learn to make you life fit it better. Habit can help, Dr.Kleitman believes. Maybe youre sleepy in the evening but feel you must stay up late anyway. Counteract your cycle to some extent by habitually staying up later than

30、 you want to. If your energy is low in the morning, but you have an important job to do early in the day, rise before your usual hour. This wont change your cycle, but youll get up steam and work better at your low point.Get off to a slow start which saves your energy. Get up with a leisurely yawn a

31、nd stretch. Sit on the edge of the bed a minute before putting your feet on the floor. A void the troublesome search for clean clothes by laying them out the night before. Whenever possible, do routine work in the afternoon and save tasks requiring more energy or concentration for your sharper hours

32、. 11.If a person finds getting up early a problem, most probably_D_A) he is a lazy person B) he refuses to follow his own energy cycleC) he is not sure when his energy is low D) he is at his peak in the afternoon or eveningC12.Which of the following may lead to family quarrels according to the

33、passage?A) Unawareness of energy cycles. B) Familiar monologuesC) A change in a family members energy cycle D) Attempts to control the energy cycle of other family members13.If one wants to work more efficiently at his how point in the morning, he should_C_A) change his energy cycle B) overcome his

34、lazinessC) get up earlier than usual D) go to bed earlier14.You are advised to rise with a yawn and stretch because it will_A_A) help to keep your energy for the days workB) help you to control your temper early in the dayC) enable you to concentrate on your routine workD) keep your energy cycle und

35、er control all dayB15.Which of the following statements is NOT TRUE?A) Getting off to work with a minimum effort helps save ones energyB) Dr.Kletman explains why people reach their peaks at different hours of day.C) Habit helps a person adapt to his own energy cycleD) Children have energy cycles, to

36、o. Passage 3你是否發(fā)現(xiàn)早上起床很困難以至于是一種痛苦？這也許可以被稱作懶惰，但克萊特曼博士有一種新的解釋。他已證明每個(gè)人都有一個(gè)日能量周期。在你工作的時(shí)候，你可能會(huì)說你很“熱”。沒錯(cuò)！一天當(dāng)中你覺得精力最為充沛的時(shí)候就是你的體溫周期達(dá)到頂峰的時(shí)候。對(duì)一些人來說，這一頂峰會(huì)在午前到來。而對(duì)另一些人來說，則到下午或是晚上才來到。（）還沒有人能夠提示為什么會(huì)這樣，但這導(dǎo)致了大家都很熟悉的那種自言自語，例如（）“該起床了，約翰！又要上班遲到了！”對(duì)這種煩惱可能性的解釋就是他的體溫與能量頂峰在晚上到來。（）當(dāng)夫婦們了解到能量周期的意義，并得知每個(gè)家庭成員的能量周期是哪一種類型的時(shí)候

37、，很多家庭爭(zhēng)端便結(jié)束了。你無法改變你的能量周期，但你了解到自己的周期之后可以使你的生活更加適合它?？巳R特曼博士認(rèn)為習(xí)慣是有幫助的。也許你很想睡覺，但覺得你無論如何都得熬夜。習(xí)慣性地延遲睡覺時(shí)間可以在一定程度上對(duì)抗你的周期。（）如果你早上能量低，但在一大清早有件很重要的工作要做，就比平時(shí)早些起床。這樣做不會(huì)改變你的周期，但你可以在能量低的時(shí)候鼓起干勁，更好地工作。（）慢慢地開始一天的工作有助于節(jié)約能量。起床時(shí)放松地打個(gè)哈欠，伸伸懶腰，在床上坐一會(huì)兒再下地。前一天晚上把干凈衣服放好，這樣就不用手忙腳亂地到處亂翻。盡可能在下午做常規(guī)工作，把需要更多能量與注意力的任務(wù)留到最佳狀態(tài)的時(shí)候來處理。、如果一

38、個(gè)人覺得早起很難，很有可能_A)他是個(gè)懶惰的家伙B)他不愿遵循自己的能量周期C)他不清楚自己什么時(shí)候能量低D)他的高峰在下午或晚上、根據(jù)本文，下面哪種情形會(huì)導(dǎo)致家庭爭(zhēng)端？A)沒有意識(shí)到存在能量周期B)熟悉的自言自語C)一名家庭成員改變了他的能量周期D)企圖控制其他家庭成員的能量周期、如果一個(gè)人想在他的能量低點(diǎn)早晨工作得更有效率，他應(yīng)該_A)改變他的能量周期B)克服他的懶惰C)比平時(shí)起得早些D)早些睡覺、建議你起床時(shí)打個(gè)哈欠，伸伸懶腰，因?yàn)檫@樣會(huì)_A)幫助你保持一天工作的能量B)幫助你在一天的開始就控制脾氣C)使你專注于常規(guī)工作D)使你全天的能量都得到控制、下面哪個(gè)說法不正確？A) 花最小的力氣

39、開始工作有助于節(jié)約能量B) 克萊特曼博士解釋了為什么人們?cè)谝惶飚?dāng)中不同的時(shí)間達(dá)到能量頂峰C) 習(xí)慣幫助人適應(yīng)自己的能量周期D) 孩子也有能量周期   大學(xué)英語四級(jí)考試閱讀材料每日一練（） Passage 4We find that bright children are rarely held back by 重點(diǎn)mixed-ability teaching. On the contrary, both their knowledge and experience are enriched. We feel that there are many disadvan

40、tages in streaming pupils. It does not take into account the fact that children develop at different rates. It can have a bad effect on both the bright and the not-so-bright child. After all, it can be quite discouraging to be at the bottom of the top grade!Besides, it is rather unreal to grade peop

41、le just according to their intellectual ability. This is only one aspect of their total personality. We are concerned to develop the abilities of all our pupils to the full, not just their academic ability. We also value personal qualities and social skills, and we find that mixed-ability teaching c

42、ontributes to all these aspects of learning.In our classrooms, we work in various ways. The pupils often work in groups: this gives them the opportunity to learn to co-operate, to share, and to develop leadership skills. They also learn how to cope with personal problem as well as learning how to th

43、ink, to make decisions, to analyse and evaluate, and to communicate effectively. The pupils learn from each other as well as from the teacher.Sometimes the pupils work in pairs; sometimes they work on individual tasks and assignments, and they can do this at their own speed. They also have some form

44、al class teaching when this is appropriate. We encourage our pupils to use the library, and we teach them the skills they need in order to do this efficiently. An advanced pupil can do advanced work: it does not matter what age the child is. We expect our pupils to do their best, not their least, an

45、d we give them every encouragement to attain this goal.16. In the passage the authors attitude towards “mixed-ability teaching” is_C_D_沒有理解mixed-ability teaching的意思A) critical B) questioning C) approving D) objective17. By “held back”(Line 1) the author means “_D_”A) made to remain in the same class

46、es B) forced to study in the lower classesC) drawn吸引 to their studies D) prevented from advancing18. The author argues that a teachers chief concern should be the development of the students_B_A) personal qualities and social skills B) total personality C) learning ability and communicative skills D

47、) intellectual abilityB19. Which of the following is NOT MENTIONED in the third paragraph?A) Group work gives pupils the opportunity to learn to work together with othersB) Pupils also learn to develop their reasoning abilitiesC) Group work provides pupils with the opportunity to learn to be capable

48、 organizers.D) Pupils also learn how to participate in teaching activities.AB20. The authors purpose in writing this passage is to _A) argue for teaching bright and not so0bright pupils in the same classB) recommend pair work and group work for classroom activitiesC) offer advice on the proper use o

49、f the libraryD) emphasize the importance of appropriate formal classroom teaching Passage 4 （16）（17）我們發(fā)現(xiàn)，聰明的孩子如果接受不按能力分班的教學(xué)，很少會(huì)因此被拖后了。相反，他們?cè)谥R(shí)和經(jīng)驗(yàn)方面都有長(zhǎng)進(jìn)。我們認(rèn)為把學(xué)生按照能力分班有很多弊端。這種做法沒有考慮到孩子們發(fā)展情形各不相同這一事實(shí)。對(duì)聰明的孩子和不太聰明的孩子都有不良影響。畢竟，在最好的那一檔里做最差的學(xué)生也夠令人氣餒了！此外，只根據(jù)人的智力水平來對(duì)人進(jìn)行分類也是頗不現(xiàn)實(shí)的。這僅僅是全部人品特征的一個(gè)方面罷了。（18

50、）我們關(guān)心的是讓所有的學(xué)生都能充分發(fā)展各方面的能力，而不僅僅是學(xué)術(shù)能力。我們也很看重個(gè)人品質(zhì)與社交技能，而我們發(fā)現(xiàn)不按能力分班的教學(xué)對(duì)學(xué)習(xí)所有這些方面都很有益。在教室里，我們以不同的方式工作。（19）（A）學(xué)生們通常會(huì)以小組為單位進(jìn)行學(xué)習(xí)；這樣他們便有機(jī)會(huì)學(xué)習(xí)相互合作、分享，以及（19）（C）培養(yǎng)領(lǐng)導(dǎo)技能。他們還能學(xué)到怎樣處理個(gè)人問題，以及（19）（B）怎樣思考，怎樣作決定，怎樣分析和評(píng)價(jià)，與怎樣進(jìn)行有效的交流。學(xué)生們不僅向老師學(xué)習(xí)，也可以互相學(xué)習(xí)。有時(shí)，學(xué)生們也會(huì)以結(jié)對(duì)的方式學(xué)習(xí)；還有時(shí)，他們自己完成個(gè)人的任務(wù)，他們可以按照自己的速度來做。在適當(dāng)?shù)臅r(shí)候，他們也要接受正規(guī)的課堂教學(xué)。我們鼓勵(lì)學(xué)

51、生們使用圖書館，所以我們要教他們所需的技巧，才能有效地利用好圖書館。一個(gè)先進(jìn)的學(xué)生可以做先進(jìn)的工作，而他的年齡多大并不重要。我們期望學(xué)生們可以最大限度而不是最小限度地發(fā)揮他們的能力，我們也會(huì)盡量鼓勵(lì)他們達(dá)到定目標(biāo)。16、在文中，作者對(duì)“不按能力分班的教學(xué)”持_態(tài)度。A） 批判的 B）懷疑的 C）贊同的 D）客觀的17、第一行的“held back”的意思是_A）可以待在同樣的班級(jí)里 B）被迫在較差的班里學(xué)習(xí)C）吸引學(xué)習(xí) D）阻礙發(fā)展18、作者的觀點(diǎn)是：教師主要應(yīng)關(guān)心學(xué)生_發(fā)展A）個(gè)人品質(zhì)與社交技能 B）整個(gè)人品特征C）學(xué)習(xí)能力與交流能力 D）智力水平19、下面哪個(gè)說法沒有在第三段提到？A） 以

52、小組為單位進(jìn)行學(xué)習(xí)給學(xué)生們學(xué)習(xí)相互合作的機(jī)會(huì)B） 學(xué)生們也要學(xué)習(xí)培養(yǎng)他們的推理能力C） 以小組為單位的學(xué)習(xí)讓孩子們有機(jī)會(huì)學(xué)習(xí)怎么做一個(gè)有能力的組織者D） 學(xué)生們還學(xué)習(xí)怎樣參與到教學(xué)活動(dòng)中去。20、作者寫本文的用意是_A） 提出要讓聰明的孩子與不太聰明的孩子在同樣的班里接受教育B） 推薦在教室活動(dòng)中采用結(jié)對(duì)或分組學(xué)習(xí)的方式C） 提出正確利用圖書館的建議D） 強(qiáng)調(diào)合理進(jìn)行正規(guī)的課堂教學(xué)的重要性   大學(xué)英語四級(jí)考試閱讀材料每日一練（） Passage 5Nursing at Beth Israel Hospital produces the best patient

53、care possible. If we are to solve the nursing shortage, hospital administration and doctors everywhere would do well to follow Beth Israels example.At Beth Israel each patient is assigned to a primary nurse who visits at length with the patient and constructs a full-scale health account that covers

54、everything from his medical history to his emotional state. Then she writes a care plan centered on the patients illness but which also includes everything else that is necessary.The primary nurse stays with the patient through his hospitalization, keeping track with his progress and seeking further

55、 advice from his doctor. If a patient at Beth Israel is not responding to treatment, it is not uncommon for his nurse to propose another approach to his doctor. What the doctor at Beth Israel has in the primary nurse is a true colleague.Nursing at Beth Israel also involves a decentralized（分散的）nursin

56、g administration; every floor, every unit is a self-contained organization. There are nurse-managers instead of head nurses; in addition to their medical duties they do all their own hiring and dismissing, employee advising, and they make salary recommendations. Each units nurses decide among themselves who will work what shifts and when.Beth Israels nurse-in-chief ranks as an equal with other vice presidents of the hospital. She also is a member of the Medical Executive Committee, which in most hospitals includes only doctors. 21. Which of the following best ch