For most of recorded history, the struggle to eat has been the main focus of human activity, and all but a handful of people were either farmers or farm workers. Starvation was ever-present threat. Even the best years rarely yielded much of a surplus to carry over as an insurance against leaner times. In the worst situation, none but the powerful could be sure of a full stomach.
Now most people in rich countries never have to worry about where the next meal is coming from. In 1900 two in every five American workers laboured on a farm: now one in 5Q does. Even in poor places such as India, where famine still struck until the mid-20th century, the assumption that everyone will have something to eat is increasingly built into the rhythm of life.
That assumption, though, leads to complacency（自满情结）. Famine has ended in much of the world, but it still stalks parts of Africa -Ethiopia, Mozambique and Zimbabwe, to name three countries, depend on handouts of food. And millions of people still suffer from malnutrition. According to the UN's Food and Agriculture Organisation（FAO）, some 2 billion of the world's 7.3 billion people do not have enough to eat. Moreover, by 2050, the total population is projected to grow to almost 10 billion. Add this to the rising demand for meat, fish, milk and eggs, which is born of prosperity and which requires extra fodder to satisfy, and 70% more food will be needed in 2050 than was produced in 2009, the year the FAO did the calculation. That is a tall order. But it is not impossible.
Since the time of Thomas Malthus, an economist writing a little over 200 years ago, people have worried that population growth would outstrip（超过）food supply. So far, it has not. But neo-Malthusians spot worrying signs. One is that in some places the productivity of staples（主食）such as rice and wheat has reached a plateau（停滞期）.Neither new strains nor fancy agrochemicals are raising yields. Nor is there much unfarmed land left that is suitable to be brought under the plough. Neo-Malthusians also suggest that, if global temperatures continue to rise, some places will become unfarmable -particularly poor, tropical regions.
These are reasonable, concerns. But they can be overcome by two things: the application and spread of technology, and the implementation of sensible government policies.
Agricultural technology is changing fast. Much of this change is brought about by rich-world farmers and by rich fanners in middle-income places like Brazil. Techniques developed in the West 一 especially genome-based breeding that can create crops with special properties almost to order 一 are being adapted to make tropical crops. Such smart breeding, in alliance with new, precise techniques of genetic modification, should break through the yield plateaus. It can also produce crops with properties such as drought and heat-resistance that will. reduce the effects of global warming. Drought-resistant maize created in this way is already on the market.
The developing world applies as little to existing farming techniques as it does to the latest advances in genetic modification. Yield plateaus are a phenomenon only of the most intensively farmed parts of the world. Extending to the smallholders and subsistence farmers of Africa and Asia the best of today's agricultural practices, in such simple matters as how much fertilizer to apply and when, would get humanity quite a long way towards a 70% increase in output.
Indeed, government policy on reducing waste more generally would make a huge difference. The FAO says that about a third of food is lost during or after harvest. In rich countries a lot of food is thrown away by consumers. In poor ones it does not reach consumers in the first place. Bad harvesting practices, poor storage and slow transport mean that food is damaged, spoiled or lost to pests. Changing that, which is mostly a question of building things like better, pest-proof grain silos and monitoring their contents properly, would take a big bite out of the 70% increase.
The neo-Malthusians may throw up their hands in despair, but consider this: despite all the apparent obstacles, from yield plateaus to climate change, in the six years following the FAO analysis cereal production rose by 11%. If growth like that continues it should not only be possible to feed the 10 billion, but to feed them well.
1.According to Paragraphs 1 and 2, we can know that most people in the modern world ______ .
A.usually take food for granted .
B.are successfully getting rid of farming
C.tend to deal with lean years skillfully
D.enjoy equal rights to get good food
2.What does the underlined sentence, in Paragraph 3 probably mean?
A.Feeding a population of almost 10 billion can be expensive.
B.A precise calculation of the food growth rate is hard to make.
C.Increasing the output of food by 70% in given years is very difficult.
D.There is no parallel to the rising demand for high-quality food in history.
3.According to the passage, neo-Malthusians ______.
A.have disproved Thomas Malthus' argument
B.have contributed to the increased output of crops
C.have found that population growth will exceed food supply
D.have claimed that climate change may influence food production
4.What can we infer from the example of the develop world in Paragraph 7?
A.Technology is of little use if it is not adopted.
B.Yield plateaus are common to see all over the world.
C.The developing world has got used to existing farming techniques.
D.More advanced agricultural practices should be introduced to the developing world.
5.The underlined part "take a big bite out of" in the last but one paragraph is closest in meaning to “______ "
A.make a big profit of.
B.take full advantage of
C.indicate the influence of.
D.reduce a significant amount of
6.What does the author think of the future of le world's food supply?
A.It is worrying. B.It is promising.
C.It is controversial. D.It is uncertain.
Somewhere in the highlands of Afghanistan, a hungry fox pounces （猛扑）on a tasty-looking leopard gecko （豹纹 壁虎）.But the lizard has a get — out — of — jail — free card: a separable tail. The dropped part waves in an energetic but uncontrolled way around long enough to distract the fox, allowing the gecko itself to run off and hide.
Leopard geckos are one of a few lizard species that possess this ability, known as autotomy （自切）.The technique is effective, but the tail can account for about a quarter of the lizard's body mass. So how do these animals adapt to losing so much of it that quickly?
When geckos lose their tail, they "take this more sprawled posture （四肢伸开的姿势）"and walk with their limbs spread out farther from their body, says Chapman University biologist Kevin Jagnandan. Most researchers initially assumed this posture was a response to a suddenly shifted center of mass. But when Jagnandan observed leopard geckos with a tail in his laboratory, he realized that they wag it as they walk, suggesting that these movements may be key to the lizards' movements.
To test this assumption, Jagnandan and his team assessed the postures of 10 geckos walking in various conditions: with their tail intact （完整的）；with their tail restricted by a small section of glued-on fishing rod （whose mass can be neglected）; and with their tail self-amputated. These comparisons allowed the researchers to distinguish the effects of lost mass from those of lost tail-wagging on the geckos’ movements.
The lizards with an immobilized tail adopted ways similar to those with no tail, the researchers reported in a study published in Scientific Reports. This result suggests the sprawling walk they adopt after losing their tail is not compensating for the missing mass but rather for the lack of tail-wagging. Jagnandan thinks tail movements help the lizards keep balance and stability as they walk. He suspects that the tails of mammals living in trees, such as cats and monkeys, serve a similar purpose.
Bill Ryerson, a biologist at Saint Anselm College, who was not involved in the study, was surprised by the findings. "We thought we had settled it ——it seemed pretty open-and-shut" that mass was the main factor, he says. The new study challenges this earlier idea in a "beautifully simple" way, Ryerson adds.
Jagnandan hopes that understanding how animals react to missing body parts could ultimately help engineers design robots that can move more efficiently as heavy loads — or even entire limbs --- are added and removed.
1.From the first two paragraphs we can learn that ______.
A.the fox likes to play with the gecko's tail
B.the fox falls for the trick of the gecko
C.moving without a tail is much tougher for the gecko
D.the gecko becomes inactive when losing its tail
2.Most researchers once thought geckos adopted the sprawled posture because ______
A.the posture was key to their movements
B.their center of mass had changed
C.the posture was their unique survival skill
D.they imitated other mammals' behavior
3.What can we know about the findings of the study?
A.They are in accordance with the expectation of Bill Ryerson.
B.They were obtained after researchers compared three geckos' movements.
C.They solved several mysteries concerning other mammals.
D.They can be applied to the field of artificial intelligence.
4.What does the passage mainly talk about?
A.Why leopard geckos prefer a habitat in the highlands.
B.How leopard geckos play hide and seek games.
C.How leopard geckos adapt to losing their tails.
D.What role tails play in leopard geckos' life.
"We must learn not to take traditional morals （道德）too seriously." So said the biologist J. B. S. Haldane in a 1923 talk on science and the future. Haldane forecasted that scientific progress would destroy every belief and value. The future would be bright only "if mankind can adjust its morality to its powers". Haldane had a point: our powers have led to challenges that have never existed before. Climate change is a threat unlike any we have ever seen. Our machines might become smarter than us. Genetic engineering（基因工程）could change humanity forever.
In the face of such challenges, our evolved moral sense often proves not enough. Part of the problem is scale （规模）.The anthropologist Robin Dunbar says we can keep no more than about 150 meaningful relationships at once. But today, all 7 billion of us are connected—if not in meaningful relationships, not in meaningless ones, either. “Society" is now too big a concept for our brains to analyze.
One result is conflicting demands that are hard to solve. The bad situation of our fellow humans makes us use every possible way to deal with climate change. But that could hurt our own way of life. And then there's the urge to just forget all that pressure and get on a plane to somewhere sunny. Given this cognitive（认知的）overload, our original emotional responses tend to win out. We do what feels right. But such responses don't necessarily produce the best results. So how can we make sure we do what really is right?
It's a hard nut, but never fear: moral philosophers are on the case. Some, such as those based at the Centre for Effective Altruism in Oxford, UK, aim to maximize the good we can do by quantifying the results of our actions. Many of their suggestions have raised eyebrows: that it may be better to become a generous banker than work for a charity, for example.
Others suggest modifying our moral brains directly, through drugs. The difficulties with this idea are obvious: who decides what makes improvement? Given the practical difficulties of large-scale morality hacking （入侵），we should perhaps stick to education. We are not simply prisoners of our emotions: we can reason our way to workable solutions. Science alone will not get us there. So no, we shouldn't take traditional morality too seriously where it fails to address modem problems.
1.J. B. S. Haldane forecasted that scientific development would ______.
A.lead to the corruption of public morals
B.present a challenge to traditional morals
C.bring disasters and fears to human beings
D.affect human beings powers of adjustment
2.We can learn from Paragraph 2 that ______.
A.collective wisdom is a good solution to modem challenges
B.Robin Dunbar thinks it is hard to build up meaningful relationships
C.our evolved moral sense is too limited to solve the problems of modem society
D.the large scale of social connections makes our relationships less meaningful
3.What is implied in the last paragraph?
A.Most people put the blame for modem problems on science.
B.Science can help with the modification of our moral brains.
C.The combination of reason and humanity can make more effective morality.
D.Human beings have a long way to go before they can overcome modem problems."
Beneath the joy of music lies the often mysterious field of music theory. But what if you could learn to understand the often intimidating （使人望而生畏的）language of key signatures, pitch （音高），mode （音乐的调式）,melody and more? What if you could recognize these components at work while listening to your favorite music? What if you could "speak" the language of music?
In Understanding the Fundamentals of Music, award winning composer and professor Greenberg offers you a spirited introduction to this magnificent language, avoiding what for many of us has long been the principal roadblock: the need to read music. With these 16 fascinating lectures, discover what parts of musical speech sound like, rather than what they look like on paper. You'll quickly find yourself listening to music with new levels of understanding and appreciation whether at a concert, at home or in your car.
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1.Anyone ordering a CD of Understanding the Fundamentals of Music will .
A.obtain a paper version for free
B.be offered the highest discount
C.be required to pay for transportation costs
D.get other musicians instruction besides Robert Greenberg's .
2.What's special about The Great Courses?
A.Its academic tests are optional.
B.It focuses on readers' speaking skills.
C.It is recommended by many a musician.
D.It is readily accessible to its subscribers.
Since the age of three, Hill had dreamed of becoming a dancer. "The only thing that I loved was dance," she told CBS News. That ambition nearly _______ in 2010. Hill, then a 17-year-old student in a small town, was in an accident that left her paralyzed from the _______ down. For most people, that would have _______ any hope of a dancing career. For Hill, it was the beginning. _______ being an obstacle, her wheelchair empowered her. "I wanted to _______ to my myself I was still 'normal'."
Hill danced in her wheelchair alongside her school dance team. "Half of my body was _______ from me," Hill told Today. "and it definitely took a lot of learning and _______ After graduation, Hill wanted to _______ her dance network to include women who had _______ various spinal cord injuries but shared her ________. "It was such an amazing experience?”
Hoping to reach more people in a ________ city, Hill moved to Los Angeles in 2014 and formed the Rollettes. "I want to ________ the stereotype （模式化观念）of wheelchair users.", Dancing on wheels can be just as artful as the foot-based ________ . In dance competitions, they rocked their bodies to ________, and struck poses in dynamic routines. They're having fun, and as the audiences' reactions ________ , the fun is infectious. Hill has ________ what many of us never will: her childhood dream. ________ the Rollettes have helped her find something else just as ________. Every year she holds a dance camp for wheelchair users to help them find their ________ strength they've never seen before. In 2019, 173 participants who used to be restricted lonely attended her camp. For many, it was the first time they'd felt they ________.
1.A.initiated B.ended C.withdrew D.postponed
2.A.head B.knee C.waist D.ankle
3.A.dashed B.quit C.lost D.abandoned
4.A.Regardless of B.Far from C.Out of D.Apart from
5.A.justify B.convince C.confirm D.prove
6.A.taken away B.cleared away C.worn away D.turned away
7.A.patience B.competence C.intelligence D.independence
8.A.accumulate B.attract C.boycott D.expand
9.A.multiplied B.submitted C.suffered D.possessed
10.A.virtue B.determination C.dimension D.identity
11.A.riper B.remoter C.larger D.busier
12.A.break off B.break up C.break in D.break down
13.A.practice B.variety C.performance D.access
14.A.music B.beats C.instructions D.directions
15.A.indicate B.express C.illustrate D.conclude
16.A.comprehended B.compensated C.adored D.attained
17.A.But B.Instead C.So D.Still
18.A.superior B.premier C.normal D.meaningful
19.A.main B.inner C.unique D.physical
20.A.scared B.matured C.belonged D.sustained
—I will hang out with friends this afternoon. May I do the homework tomorrow?
—______ You have to finish it today.
A.What of it? B.You don't say
C.What's up D.Not on your life!
