人教版选修八unit 2 cloning learning about language课时作业 (2).docx

unit 2 cloning learning about language课时作业i阅读理解abrushing your teeth regularly could help to prevent bowel(肠) cancer，a study suggests.this is because the mouth bacteria that cause bleeding gums(牙龈) can travel via the blood to the bowel where they could result in cancer or worsen existing tumours(肿瘤).the bug fusobacterium(梭杆菌) has been found to be hundreds of times more common in cancerous tumours than in normal cells.now researchers have found that the bacteria can make precancerous growths in the bowel turn cancerous.they can also make any existing tumours in the bowel grow larger.scientists are doing research on how the bacteria make their way to the bowel through the blood stream.one theory is that it may happen if a person has bleeding gums.the researchers found that the bacteria have a protein that allows them to stick to sugar molecules attached to friendly growths called polyps(息肉) as well as cancer tumours in the bowel.the bacteria are anaerobicthey do not breathe oxygenso are well suited to live in the bowel.after sticking to the polyps or tumours，the presence of the bacteria promotes their growth，according to the research.by targeting this process，the researchers believe that it may lead to new drugs to treat bowel cancer which around 1 in 20 of us will develop in our lifetimes.coauthor wendy garret，a professor at harvard university said a greater understanding of the mechanism(机理)may help stop people developing cancerous tumours.she added，“more importantly，our findings suggest that the new drugs could potentially prevent these bacteria from worsening bowel cancer.”as well as worsening cancer，the bacteria have also been found to worsen the bowel condition ulcerative colitis(溃疡性结肠炎)，which in turn is also linked to cancer.so，the researchers warn that mouth health may be an indicator of other lifestyle factors linked to cancer.1.from the first paragraph，we can learn that .a.bowel cancer may be cured by brushing teeth regularlyb.scientists have found the reason for bowel cancerc.brushing teeth regularly helps you fight bad breathd.good mouth health has a good effect on preventing bowel cancer2.according to researchers，if a person suffers from bleeding gums， .a.bacteria may enter the bowel with blood and increase the risk of cancerb.the bug fusobacterium may decrease in the cellsc.measures must be taken to prevent blood flowing into boweld.he should go to the dentist to have the teeth pulled out3.chances are that through this research.a.people will get rid of the symptoms of bleeding gumsb.people will never suffer from bowel cancerc.scientists will develop more effective drugs to deal with bowel cancerd.scientists will find ways to stop fusobacterium worsening gums4.whats the authors purpose in writing this passage?a.to tell people not to worry about bowel cancer.b.to warn people of the danger of bowel cancer.c.to educate people about the ways to stop bleeding gums.d.to make people understand the importance of brushing teeth regularly.bthe domestic cat is a contradiction.no other animal has developed such a close relationship with human，while at the same time demanding and getting such selfdetermining movement and action.the cat manages to remain a tame(驯化的) animal because of the process of its upbringing.by living both with other cats(its mother and brother and sisters) and with human(the family that has adopted it) during its babyhood，it is considered to belong to both species.it is like a child that grows up in a foreign country and as a consequence becomes bilingual(双语的).the young cat becomes bimental.it may be a cat physically but mentally it is both feline(猫科的) and human.once it is fully adult，however，most of its responses are feline ones，and it has only one major reaction to its human owners.it treats them as pseudo(假的) parents.this is rather different from the kind of bond that develops between human and dog.the dog sees its human owners as pseudo parents，as does the cat.on that score the process of attachment is similar.but the dog has an additional link.canine(犬科的) society is grouporganized；feline society is not.dogs live in packs with tightly controlled status relationships among the individuals.there are top dogs，middle dogs，and bottom dogs and under natural circumstances they move around together，watching and following one another the whole time.so the adult pet dog sees its human family both as pseudo parents and as the dominant(主宰的) members of the pack，hence its wellknown reputation for obedience and loyalty.cats do have a complex social organization，but they never hunt in packs.in the wild，most of their day is spent in individual stalking(潜行追踪).going for a walk with a human，therefore，has no appeal for them.and as for“coming to heel”and learning to“sit”and “stay”，they are simply not interested.such drills have no meaning for them.because of this difference between domestic cats and domestic dogs，catlovers tend to be rather different from doglovers.as a rule catlovers have a stronger personality bias(偏向) toward working alone，away from larger group.artists like cats；soldiers like dogs.the highlypraised “group loyalty” phenomenon cant be seen in both cats and catlovers.if you are a company person，a member of the gang，or a person picked for the military team，the chances are that at home there is no cat curled up in front of the fire.the ambitious politician，the professional athlete，these are not typical catowners.it is hard to picture football players with cats in their lapsmuch easier to imagine them taking their dogs for walks.those who have studied catowners and dogowners as two distinct groups report that there is also a gender bias.the majority of catlovers are female.this bias is not surprising in view of the division of labor obvious in the development of human societies.prehistoric males became specialized as grouphunters，while the females concentrated on foodgathering and childbearing.this difference contributed to a human males “pack mentality” that is far less marked in females.wolves，the wild ancestors of domestic dogs，also became packhunters，so the modern dog has much more in common with the human male than with the human female.the argument will always go onfeline selfsufficiency and individualism against canine camaraderie (友情) and goodfellowship.but it is important to stress that in making a valid point i have caricatured the two positions.in reality, there are many people who enjoy equally the company of both cats and dogs.and all of us，or nearly all of us，have both feline and canine elements in our personalities.we have moods when we want to be alone and thoughtful，and other times when we wish to be in the center of a crowded，noisy room.5.the primary purpose of the passage is to .a.advocate dogs as making better pets than catsb.distinguish the different characteristics of dogs and catsc.show the poor nature of dogs because of their loyalty characteristicsd.emphasize the role that human plays in the personalities of domestic pets6.according to the passage，the domestic cat is a contradiction because .a.it possesses the physical characteristics of both feline and humanb.it cant be tamed and will always keep its wild habitsc.it refuses to be dominated despite living comfortably with humand.although it plays the part of a pet，it really dominates human beings7.the underlined sentences in the second paragraph are used to stress .a.the disharmonious relationship between cats and human beingsb.a difference between cats and dogs that emphasizes cats naturec.the ignorance of dogs，which makes them more loyal petsd.the laziness of cats that keeps them from being pack animals8.the author suggests in the third paragraph that catlovers are than doglovers.a.less dependent b.less creativec.more successful d.more outgoing9.the fourth paragraph indicates that human females .a.preferred to raise domestic dogs to help with foodgatheringb.developed independent roles that required less group behaviorc.had to gather food because they were not strong enough to huntd.were negatively affected by the division of labor of human societies10.the underlined four sentences in the last paragraph provide .a.a summary of the points made earlierb.a reason for the statements made earlierc.an adjustment of the position taken earlierd.an example of the main points made earlierii.任务型阅读(共10小题；每小题1分，满分10分)请认真阅读下面短文，并根据所读内容在文章后表格中的空格里填入一个最恰当的单词。注意：每个空格只填一个单词。have you noticed that birds fly in a “v” formation when migrating？especially when travelling long distances，maintaining this pattern becomes important for many species that travel thousands of miles.flying long distances can be exhausting. it is important for the birds to conserve energy. how do they do it?this question has constantly puzzled researchers on the science of this “v” formation. while aerodynamics and upwashes have explained the scientific phenomenon behind this flying behavior，scientists have often wondered how a flock of birds solve the “social dilemma” of who leads the flock.new research by a group of scientists from the uk，germany and austria who studied the northern bald ibis，may help us understand how birds handle this.when a bird glides or flaps its wings，it creates wingtip vortexes(涡旋)or circular currents of air around its wings. the forward motion meanwhile pushes air underneath its wings. as the air squeezes around a birds wingtips，it creates a current moving upcalled an upwash. birds right behind position themselves to make use of this rising current！this makes it much easier for the birds behind to ride without using much energy at all.meanwhile，the birds that follow can time their wing beats to match the upwardsmoving air coming from the front birds，minimizing effort on their part.to lead a group of birds can be quite draining. taking turns helps as the birds in front provides a lift for others flying behind it in formation.observation of data from gps tracking devices fitted to the birds ultimately gave clues to the scientists that these birds typically fly in pairs. the time bird a flies in front of bird b correlates almost exactly with the amount of time bird b is in front of bird a. they take turns with the birds repeatedly swapping positions as followers and leaders!researchers had suspected that birds cooperated with each other in some way，but they were surprised that the pattern was so clear and the mechanism was so simple. birds do not need to watch all the other birds in the flock. they just have to match up with one other bird. it is very simple and robust(耐用的).“pairwise matching”，as the researchers call this phenomenon，is probably used by many other bird species to increase their chance of survival while reducing the amount of energy they use.there is much to be learned from observing birds. it takes a team to do achieve big goals. can we work in groups to maximize our strengths？maybe we too can.introductionbirds migration comes in a “v” formation，especially in longdistance flying.longdistance flying can make birds 1. from physical exhaustion，thus conserving energy when travelling becomes important.how birds save energy while migrating and how they choose their leading bird are still the 2. aspects of this “v” formation flying behavior.how birds take 3. of the “v” formation riding the windwhile flying，a bird creates an upwash，which can be made use of by the birds right behind，thus saving 4. .the following birds beat their wings at a 5. time to match the upwardsmoving air so as to make less effort.taking turnsthe leading bird needs to offer a 6. to others flying behind，which 7. the chance of its using up its strength and taking turns can prevent this appearing.birds fly in pairs when migrating and their leaders 8. with the followers in a repeated and regular pattern.when flying，birds only need to match up with one other bird 9. than watching all their companions.conclusionsmany other birds use such “pairwise matching” to survive by reducing their energy usage.we should learn from birds to achieve our big goals through 10. .iii.书面表达(满分25分)(社会文化)假设你是李华，在美国的某中学做交流生。你的同学对中国宴请赴约的习俗很感兴趣， 特请你用英语写一篇发言稿， 介绍中国的宴请习俗。内容包括：宴请场所；就餐习俗；饮酒习俗；宴会结束。注意：1.词数150左右；2.信的开头已为你写好，不计入总词数；3.可适当增加细节，以使行文连贯。参考词汇：宴会banquetladies and gentlemen，i feel greatly honored to be here to tell you something about chinese banquet customs. 参考答案语篇解读一项研究表明，定期刷牙可有助于预防肠道癌。这是因为人的口中有可以引起牙龈出血的细菌，而这些细菌能够通过血液进入肠道，从而引发癌症或者使已有的肿瘤症状恶化。1.d细节理解题。根据第一段第一句可知，口腔健康有助于预防肠道癌。故选d。2.a细节理解题。根据第一段最后一句可知，根据研究人员的观点，如果一个人牙龈出血，细菌就可能会通过血液进入肠道，从而增加癌症的风险。故选a。3.c细节理解题。根据第八段可知，通过这项研究，科学家们很可能会开发出更有效的药物来治疗肠癌。故选c。4.d写作意图题。综合全文尤其是第一段第一句和最后一段可知，研究表明，定期刷牙可有助于预防肠道癌。由此可见，作者写这篇文章的目的是让人们明白定期刷牙的重要性。故选d。语篇解读虽然猫和狗都是家养的动物，但是它们却不一样。人与猫之间的关系和人与狗之间的关系截然不同。猫科动物的特点是自我满足和个人主义，而犬科动物则是团结友爱和亲密无间。5.b写作意图题。综合全文尤其是第二段、第三段和最后一段的第一句可知，本文的主要目的是为了区分狗和猫之间不同的特点。故选b。 6.c细节理解题。根据第一段第二句可知，家猫是矛盾的动物，尽管