In its early history, Chicago had floods frequently, especially in the spring, making the streets so muddy that people, horses, and carts got stuck. An old joke that was popular at the time went something like this: A man is stuck up to his waist in a muddy Chicago street. Asked if he needs help, he replies, "No, thanks. I've got a good horse under me."

    The city planner decided to build an underground drainage (排水) system, but there simply wasn't enough difference between the height of the ground level and the water level. The only two options were to lower the Chicago River or raise the city.

    An engineer named Ellis Chesbrough convinced me the city that it had no choice but to build the pipes above ground and then cover them with dirt. This raised the level of the city's streets by as much as 12 feet.

    This of course created a new problem: dirt practically buried the first floors of every building in Chicago. Building owners were faced with a choice: either change the first floors of their buildings into basements, and the second stories into main floors, or hoist the entire buildings to meet the new street level. Small wood-frame buildings could be lifted fairly easily. But what about large, heavy structures like Tremont Hotel, which was a six-story brick building?

    That's where George Pullman came in. He had developed some house-moving skills successfully. To lift a big structure like the Tremont Hotel, Pullman would place thousands of jackscrews (螺旋千斤顶) beneath the building's foundation. One man was assigned to operate each section of roughly 10 jackscrews. At Pullman's signal each man turned his jackscrew the same amount at the same time, thereby raising the building slowly and evenly. Astonishingly, the Tremont

    Hotel stay open during the entire operation, and many of its guests didn't even notice anything was happening. Some people like to say that every problem has a solution. But in Chicago's early history, every engineering solution seemed to create a new problem. Now that Chicago's waste water was draining efficiently into the Chicago River, the city's next step was to clean the polluted  river.

    “Nature and Nurture”

    People have wondered for a long time how their personalities and behaviour are formed. However, it is not easy to explain why one person is intelligent and another is not, or why one is cooperative and another is 1.

    Social scientists are of course2interested in these types of questions. They want to explain why we possess certain characteristics and exhibit certain behaviour. There are no clear answers yet, but two3schools of thought on the matter have developed. As one might expect, the two approaches are very different from each other, and there is a great deal of debate between4of each theory. The controversy(争论) is often conveniently referred to as “nature and nurture”.

    Those who5the “nature” side of the conflict believe that our personalities and behaviour patterns are6determined by biological factors. That our environment has little, if anything, to do with our abilities, characteristics and behaviour is7to this theory. Taken to an extreme, this theory states that our behaviour is predetermined to such a great degree that we are almost completely governed by our8.

    Supporters of the “nurture” theory, or, as they are often called, 9, claim that our environment is more important than our biologically based instincts in determining how we will act. A behaviorist, B. F. Skinner, sees humans as beings whose behaviour is almost completely10by their surroundings. The behaviorists' view of the human being is quite mechanistic. They state that, like machines, humans respond to 11stimuli(刺激) as the basis of their behaviour.

    Socially and politically, the consequences of these two theories are 12. In the US, for example, blacks often score below whites on standardized intelligence tests. This leads some “nature” supporters to conclude that blacks are genetically lower in status than whites are. Behaviorists, 13, say that the differences in scores are due to the fact that blacks are often robbed of many of the educational and other environmental advantages that whites enjoy, and that, as a result, they do not develop the same14that whites do.

    Neither of these theories can yet fully explain human behaviour. As a matter of fact, it is quite15that the key to our behaviour lies somewhere between these two extremes and that the controversy will continue for a long time is certain.

    Directions: For each blank in the following passages there are four words or phrases marked A, B, C, and D. Fill in each blank with the word or phrase that best fits the context.

    Microsoft Corp founder Bill Gates caught people's eye in a recent interview, when he suggested that robots should be taxed in, order to help humans keep their jobs. Gates is only one of many people in the tech world who have worried about automation and its 1 to workers.

    It's easy to see why the tech world is 2. The rise of machine learning has increased the fear that 3 humans could simply become out of date--4, 3.5 million American truck drivers might soon find their jobs threatened by driverless trucks. Though in the past, technology usually complemented workers 5 replacing them, there's no law of nature saying the technology of the future will work the same. A few economists even claim that cheap automation has already 6 income from workers to company owners.

    Another 7 is that even if the mass of humanity ultimately does find new ways to add value by complementing new technology—to “race with the machines,” as economist Erik Brynjofsson puts it—this transition could take a long time and hurt a lot of people. As Bloomberg View's Tyler Cowen has noted, wages in Britain fell for four decades at the start of the Industrial Revolution. More 8, we've seen very slow and painful adjustment to the impact of globalization. If the machine learning revolution hurts workers for 40 years before ultimately helping them, it might be worth it to 9 that revolution and give them time to adjust.

    The main argument against taxing the robots is that it might hold back 10. Growth in rich countries has slowed markedly in the past decade, suggesting that it's getting harder and harder to find new ways of doing things. Stagnating productivity, combined with falling business investment, suggests that 11 of new technology is currently too slow rather than too fast—the biggest problem right now isn't too many robots, it's too few. Taxing new technology, however it's done, could make that slowdown worse.

    The problem with Gate's basic proposal is that it's very hard to tell the difference between new technology that12 humans and new technology that replaces them. This is especially true over the long term. Power looms（织布机）replaced human weavers back in the Industrial Revolution. 13, people eventually became more productive, by learning to operate those looms. If taxes had slowed the development of power looms, the eventual improvements would have come later.

    This is a powerful argument 14 the taxation of automation. Gates is right to say that we should start thinking ahead of time about how to use policy to mitigate（缓和）the unintended consequences of automation. But given the importance of sustaining innovation, we should look at 15 policies.

What's all this tree一 planting for?" I was asked when I began writing about 1 a piece of land I had bought in Somerset. The truth is, I just love trees. And I am not 2. As I get older, all I really 3 is to plant trees, Prince Charles says in a BBC documentary in which he is 4 in the wood he planted on the day Prince George was born.

    There are 5 and wonderful trees in our cities and villages. They were planted, or self- sown, years, even centuries ago. We take them for granted, 6 the creatures living among them, remain in ignorance of the 7 trees are doing us(cleaning the air, for instance) and cut them down for new 8. Yet we keep a feeling of 9 for them. This may account for the 10 the government faced in 2010 when it sought to sell off publicly owned woods, and for the wide support that the Woodland Trust (a tree-protecting charity) 11.

    Trees need 12, which is why I, a city-resident, bought my Somerset woodland in 1999. At that time, climate change was already well proved, 13 my hopes of planting long-lived oaks and pines gradually developed into anxiety about their 14. Tree diseases new to the UK, wind, drought and flood were all 15 against them.

    But I did not 16 things to move so fast. The woodland is still good, the new trees are growing like mad, but the creatures are 17. The rabbits have disappeared and the owl has moved. The bees and butterflies are 18 there but in smaller numbers. How can this happen on land 19 pesticides (杀虫剂)？Surely, it indicates we need to give nature the chance to restore its own 20. Meanwhile, I love my wood, and so do many of its visitors. And tree-planting has done wonders for restoring my balance town and country.

    Wildlife has been greatly threatened in the modem age. There are species (物种) that are 1 every day. The white-naped crane is a typical example. So scientists are trying their best to 2 the species from going out of existence.

    Chris and Tim work at a zoo, helping endangered cranes with their 3. Emma, a female crane, has been in their 4 since she arrived in 2004.

    Born at an international crane foundation, Emma was 5 by human caretakers. This led to an unexpected 6, though she had a wonderful time there. Emma had 7 taken herself as a crane and become deeply attached to humans. She 8 to live with male cranes, and even had a 9 for killing some of them, which made it 10 for her to become a mother.

    11, the two zookeepers didn't want to see the extinction (灭绝) of this precious species. With their patience and efforts, they successfully developed a 12 of artificial breeding (人工繁殖) and natural reproduction. This 13 Emma to give birth to five baby cranes.

    The two keepers are proud of their productive work. But before they can be 14, more efforts must be made, because the population of the crane in the wild is on the 15, and many other species appear headed toward extinction. 16, not everyone has realized that wildlife has thoughts, feelings, and most importantly, equal rights to survive.

    How can we 17 the ever-widening gap that separates us from other animals? Chris and Tim offered us the 18: human beings took it for granted that their 19 held all the solutions, but maybe their hearts can be a better 20.

Machines work well at a constant speed —and the faster the better.Whether they are spinning cotton {#blank#}1{#/blank#}dealing with numbers,regular,repetitive actions are what they excel at.

Increasingly,our world is being designed by machines and for machines.We adapt to machines and hold ourselves to their standards:People {#blank#}2{#/blank#}(judge)by the speed at which they respond, not the quality of their response."Always on"becomes something to take pride {#blank#}3{#/blank#}.When I ask people {#blank#}4{#/blank#} they are doing,they almost always answer "busy".Ticking things off the "to do"list becomes{#blank#}5{#/blank#}means of defining ourselves. {#blank#}6{#/blank#} (occupy)if not with work then with family or our social networks,most of us feel exhausted.

A few years ago,I became very interested in what it meant {#blank#}7{#/blank#}(pause).I started to notice where pauses show up in my own work and life.For example,I realized when I was writing,a short walk was a(n) {#blank#}8{#/blank#}(effective)way to focus than concentrating harder.The small walk acted as a pause, {#blank#}9{#/blank#}(enable)me to rest,reflect or refresh,appreciate and break a block in my {#blank#}10{#/blank#}(creative).I realized that pause is not nothing!

A minute eating ice-cream is not the same as a minute doing push-ups.Even time itself isn't a uniform raw material —as the physics of Einstein shows.