1. Passage Twenty-OneWhat will man be like in the future—in 5，000 or even 50，000 years from now? We can only make guesses， of course， but we can be sure that he will be different from what he is today.For man is slowly changing all the time.Let us take an obvious example.Man， even five hundred years ago， was shorter than he is today.Now， on average， men are about three inches taller.Five hundred years is relatively short period of time， so we may assume that man will continue to grow taller.Again， in the modern world we use our brains a great deal.Even so， we still make use of only about 20% of the brain’s capacity.As time goes on， however， we shall have to use our brains more and more， and eventually we shall need larger ones.This is likely to bring about a physical change to the head， in particular the forehead will grow larger.Nowadays our eyes are in constant use.In fact， we use them so much that very often they become weaker and we have to wear glasses.But over very long period of time it is likely that man’s eyes will grow stronger.On the other hand， we tend to make less use of our arms and legs.These， as a result， are likely to grow weaker.At the same time， however， our fingers will grow more sensitive because they are used a great deal in modern life.But what about hair? It will probably disappear from the body altogether in course of time because it does not serve a useful purpose any longer.In the future， then， both sexes are likely to be bald.Perhaps all this gives the impression that future man will not be a very attractive creature to look at.This may well be true.All the same， in spite of all these changes， future man will still have a lot in common with us.He will still be a human being， with thoughts and emotions similar to our own.The passage tells us about ().

3. Passage Thirty-ThreeWe all know that DNA has the ability to identify individuals but， because it is inherited， there are also regions of the DNA strand which can relate an individual to his or her family (immediate and extended)， tribal group and even an entire population.Molecular Genealogy (宗谱学)can use this unique identification provided by the genetic markers to link people together into family trees.Pedigrees (家谱)based on such genetic markers can mean a breakthrough for family trees where information is incomplete or missing due to adoption， illegitimacy or lack of records.There are many communities and populations which have lost precious records due to tragic events such as the fire in the Irish courts during Civil War in 1921 or American slaves for whom many records were never kept in the first place.The main objective of the Molecular Genealogy Research Group is to build a database containing over 100，000 DNA samples from individuals all over the world.These individuals will have provided a pedigree chart of at least four generations and a small blood sample.Once the database has enough samples to represent the world genetic make-up， it will eventually help in solving many issues regarding genealogies that could not be done by relying only on traditional written records.Theoretically， any individual will someday be able to trace his or her family origins through this database.In the meantime， as the database is being created， molecular genealogy can already verify possible or suspected relationships between individuals.“For example， if two men sharing the same last name believe that they are related， but no written record proves this relationship， we can verify this possibility by collecting a sample of DNA from both and looking for common markers (in this case we can look primarily at the Y chromosome (染色体)，” explains Ugo Perego， a member of the BYU Molecular Genealogy research team.The Molecular Genealogy Research Group is building a database for the purpose of ().

8.The house was very quiet， ()as it was on the side of a mountain.

A. 　isolated

B. 　isolating

C. 　being isolated

D. 　having been isolated

39. Questions 36 to 40 are based on the following passage.Some people have said aging is more a slide into forgetfulness than a journey towards wisdom.However， a growing body of research suggests that late-in-life learning is possible.In reality， education does an aging brain good.Throughout life， people’s brains constantly renovate themselves.In the late 1960s， British brain scientist Geoffrey Raisman spied growth in damaged brain regions of rats through an electron microscope; their brains were forging new connections.This meant brains may change every time a person learns something new.Of course， that doesn’t mean the brain isn’t affected by the effects of time.Just as height usually declines over the years， so does brain volume: Humans lose about 4 percent every decade starting in their 40s.But that reduction doesn’t necessarily make people think slower; as long as we are alive and functioning， we can alter our brains with new information and experiences.In fact， scientists now suspect accumulating novel experiences， facts， and skills can keep people’s minds more flexible.New pathways can strengthen our ever-changing mental structure， even as the brain shrinks.Conventional fixes like word puzzles and brain-training apps can contribute to mental durability.Even something as simple as taking a different route to the grocery store or going somewhere new on vacation can keep the brain healthy.A desire for new life challenges can further boost brainpower.Research about aging adults who take on new enterprises shows improved function and memory as well as a reduced risk of mental disease.Openness—a characteristic defined by curiosity and a desire for knowledge—may also help folks pass brain tests.Some folks are born with this take-in-the world attitude， but those who aren’t as genetically gifted aren’t necessarily out of luck.While genes can encourage an interest in doing new things， a 2012 study in the journal Psychology and Aging found completing reasoning tasks like puzzles and number games can enhance that desire for novel experiences， which can， in turn， refresh the brain.That’s why brain scientist Richard Kennedy says “It’s not that old dogs can’t learn new tricks.It’s that maybe old dogs don’t realize why they should.”What does the author say can contribute to the improvement of brain function?

A. 　Being curious and desiring knowledge.

B. 　Being eager to pass brain tests at an old age.

C. 　Rising to life’s challenges and avoiding risks.

D. 　Boosting immunity to serious mental diseases.

41.A hobby is something that you never get tired of—the more time you devote to it， the more fun you will have.

1. Passage ThirtyThe Chinese have used a method called acupuncture (针灸)to help perform operations for about 4， 000 years without putting the patient to sleep.This involves inserting flexible needles into certain parts of the body.The needles are available in a number of stores in China and everyone may buy them.To learn how to use needles takes about one month of training.But to be skillful requires greater time.The person who performs the acupuncture knows how to put in the needles so the needles themselves are not painful.This person also knows where to place the needles so the patient feels no pain in the area where the operation is to be performed.In the past， a particular operation might require 25 or more needles placed in various parts of the body.But now this operation requires only 3 or 4 needles.Today， the Chinese doctors are trying to learn more about acupuncture.They are trying to develop a convincing theory to explain how the needles work in preventing pain， or why a needle in the wrist， for example， would prevent the pain in the area of the mouth.A patient who needs an operation is given a choice between having acupuncture or having one of the chemicals used for putting him to sleep.It has been estimated that over half of the patients choose acupuncture because there is no sickness after the operation whereas the chemical may make the patient sick for a few hours or a day.Acupuncture is ().

1.有些人认为，大学生要多些社会实践，为将来工作做准备。2.有些人认为，大学生要把时间和精力放在学习上。3.你的观点是什么?

2. Passage Thirty-OneAdam Smith was the first person to see the importance of the division of labor.He gave us an example of the process by which pins were made in England.“One man draws out the wire， another strengthens it， a third cuts it， a fourth points it， and a fifth gives it a head.Just to make the head requires two or three different operations.The work of making pins is divided into about eighteen different operations， which in some factories are all performed by different people， though in others the same man will sometimes perform two or three of them.”Ten men， Smith said， in this way， turned out twelve pounds of pins a day or about 4，800 pins a worker.But if all of them had worked separately and independently without division of labor， they certainly could not have made twenty pins in a day and not even one.There can be no doubt that division of labor is an efficient way of organizing work.Fewer people can make more pins.Adam Smith saw this， but he also took it for granted that division of labor is itself responsible for economic growth and development and it accounts for the difference between expanding economies and those that stand still.But division of labor adds nothing new， it only enables people to produce more of what they already have.Adam Smith saw that the division of labor ().

5.I was ()the point of telephoning him when his letter arrived.

A. 　to

B. 　on

C. 　at

D. 　in

38.They found the lecture hard ().

A. 　to be understood

B. 　to understand

C. 　for understanding

D. 　to have been understood

1. Passage SixteenJustin was always prepared.His motto was “Never throw anything out， you never know when it might come in handy.” His bedroom was so full of flat bicycle tires， bent tennis rackets， deflated basketballs， and games with missing pieces that you could barely get in the door.His parents pleaded him to clean out his room.“What use is a fish tank with a hole in the bottom?” his father asked.But Justin simply smiled and repeated his motto， “Never throw anything out， you never know when it might come in handy.”When Justin was away from home， he always carried his blue backpack.He liked to think of it as a smaller version of his bedroom——a place to store the many objects that he collected.It was so worn and stretched that it hardly resembled a backpack anymore.It was full of the kind of things that seemed unimportant， but when used with a little imagination， might come in handy.Justin had earned a reputation for figuring things out and getting people out of otherwise hopeless situations.Many of his classmates and neighbors sought him out when they needed help with a problem.On the first day of school， his friend Kenny， came looking for Justin.“Do you think you have something in your bag that could help me remember my locker combination?” he asked.“I lost the paper it was written on.I have science class in two minutes and if I’m late on the first day it’ll make me look bad for the rest of the year.” Kenny looked genuinely worried.“Relax，” Justin said， taking his backpack off and opened it.“Remember how you borrowed my notebook in homeroom to write the code down? Well， I know how we can recover what you wrote.”He took the notebook and a soft lead pencil out of his bag.The page that Kenny had written on had left faint indentations (旧凹痕)on another page in the notebook.Justin held the pencil on its side and rubbed it lightly over the indentations.Slowly but surely the numbers of the locker combination appeared in white， set off by the gray pencil rubbings.“That’s amazing!” Kenny said.“I owe you one.” And he dashed off to open his locker.Why is Justin’s room such a mess?