Summary
The Super Strength of Spider Webs
The ability of fictional superhero Spider-Man to swing off city skyscrapers using his sticky web has fascinated many of us. But however amazing it appears to be, the superpower is unrealistic, right? Not completely, scientists say.
Spider silk is in itself a very strong material. In fact, it is about five times stronger than steel in weight-for-weight terms. Even so, this doesn’t thoroughly explain the strength of spider webs. It was not until recently that scientists discovered why spider webs are able to withstand huge forces.
The scientists found through a study that it is not just the remarkable strength of the silk spiders spin, but also a web’s intricate design that increases its durability. The creation of a typical web uses up a huge amount of a spider’s energy, so it contains a series of features which prevent major repairs from being needed.
Its complex structure means that when a single strand of web breaks, the overall strength of the web increases rather than weakens. Removing up to 10 percent of the threads from various areas made the web not weaker but actually up to 10 percent stronger. When a weight was applied, only one thread broke – so the spider could do minor repairs rather than start from scratch.
In previous studies, researchers also found the silk itself has an ability to soften or stiffen to withstand different types of loads – unlike any other natural or man-made fiber. In tests against three other materials made into similar webs, the spider silk was six times more resilient to damage when subjected to falling branches or high winds.
The scientists believe the findings could be used to help design a new generation of super strength materials. The intricate design of the spider web could be used in many areas of life to contain damage to a small area, said study co-author Markus Buehler, of the Massachusetts Institute of Technology.
Translation
1.按照惯例，参与批改考卷的老师不能使用任何电子设备。 (access)
2.每天仅准许两百名游客进入博物馆参观，因为里面陈列的物品极其珍贵。 (admit)
3.直到获悉儿子被心仪的私立小学录取时，这个多愁善感的妈妈才松了一口气。 (It …)
4.忠言逆耳利于行，这个道理尽人皆知，但是这个固执的老头是否有可能会听从你的建议呢？ (possibility)
Bicycles, roller skates and skateboards are dangerous. And don’t get me started on walking. But I’m glad I didn’t spend my childhood trapped indoors to protect me from every bump and bruise. “That which does not kill us makes us stronger.” 1. And now technology has become the new field for the age-old battle between adults and their freedom-craving kids.
Locked indoors, unable to get on their bicycles and hang out with their friends, teens have turned to social media and their mobile phones to socialize with their peers. What they do online often mirrors what they might otherwise do if their mobility weren’t so heavily limited in the age of helicopter parenting. Social media and smartphones have become so popular in recent years. 2.
As teens have moved online, parents have projected their fears onto the Internet, imagining all the potential dangers that youth might face – from violent strangers to cruel peers to pictures or words that could haunt them on Google for the rest of their lives.
Rather than helping teens develop strategies for negotiating public life and the potential risks of interacting with others, fearful parents have focused on tracking, monitoring and blocking. 3. “Protecting” kids may feel like the right thing to do, but it gradually weakens the learning that teens need to do as they come of age in a technology-soaked world.
The key to helping youth navigate contemporary digital life isn’t more restrictions. It’s freedom-plus communication. What makes the digital street safe is when teens and adults collectively agree to open their eyes and pay attention, communicate and negotiate difficult situations together. Teens need the freedom to wander the digital street, but they also need to know that caring adults are behind them and supporting them wherever they go. The first step is to turn off the tracking software. 4.
Mental illness and disability were family problems for English people living between 1660 and 1800. Most women and men who suffered from mental illness were not institutionalized as this was the period before the extensive building of mental hospitals. Instead, they were housed at home, and cared for by other family members.
Now a new study by Cambridge historian Dr. Elizabeth Foyster will reveal the impact on families of caring for mentally ill and disabled relatives.
Much has been written about the insane themselves but few studies have considered mental illness from the perspective of the carers. The lifetime burden of caring for those individuals whose mental development did not progress beyond childhood, and who contemporaries labeled as ‘idiots’ or ‘fools’, has been little explored by historians. Foyster’s research, which has been funded by the Leverhulme Trust, will carefully examine the emotional and economic consequences for families at a time when the Poor Law bound them to look after their mentally ill and disabled family members.
By asking key questions about the impact of ‘care in the community’ in the 18th century, Foyster hopes that her research will bridge social and medical history. Specifically, she aims to provide an historical perspective for contemporary debates such as how resources can be stretched to provide for children with learning difficulties and an aging population.
“The stresses and strains of family were worsened by high infant mortality and low life expectancy, and many individuals were pushed towards mental breakdown,” she explained. “Moreover, inherited conditions, senility(高龄) and what today would be described as ‘special needs’ could put great emotional demands on family members who had primary responsibility for their sick or disabled relatives.”
The research will shed light upon how caring for the mentally ill and disabled raised difficult issues for families about the limits of intergenerational responsibility, and whether family ties were weakened or strengthened by the experience. The questions of how far shame was attached to having insanity or idiocy within a family, and at what point families began to seek outside help, will also be addressed.
“The family must have seemed an inescapable feature of daily life between 1660 and 1800,” said Foyster. “Although there were those who were abandoned and rejected, for the majority, mental disability was accommodated within the family unit. I aim to get to the heart of what this really meant for people’s lives.”
1.Which is NOT the reason why those mentally ill and disabled were not institutionalized from 1660 to 1800?
A.Mental illness and disability were family problems then.
B.The extensive building of mental hospitals didn’t start yet.
C.They were abandoned by the government and the family.
D.The family would be found guilty if they didn’t care for them.
2.Why does Foyster want to carry out this study?
A.Because it can provide some food for thought for some current social issues.
B.Because the stresses and strains of family life have driven many people crazy.
C.Because she’s looking for ways to communicate with the sick or disabled people.
D.Because the limits of intergenerational responsibility in such families, interest her.
3.Which question will NOT be studied in the research?
A.How should resources today be stretched to provide for an aging population?
B.How did caring for the sick and disabled affect the family’s earning power?
C.How shameful did a family feel when their insane or disabled relatives were found out?
D.At what point did those families have to begin to look for outside help?
4.The passage is written in order to ________.
A.reveal the impact on families of caring for mentally ill and disabled relatives
B.provide an historical perspective to contemporary debates
C.shed light upon whether family ties were weakened or strengthened
D.introduce a new historical study carried out by a Cambridge historian
The global energy crisis is approaching. What can we do? Here are some steps you can take.
Cooling puts the greatest stress on your summer energy bill and the power grid. Just as a tune-up for your car can improve your gas mileage, a yearly tune-up of your heating and cooling system can improve efficiency and comfort. Clean or replace filter monthly or as needed.
For central air conditioning systems and room air conditioners, look for the ENERGY STAR, the federal government’s symbol for energy efficiency. For central air, purchase the system with the highest possible Seasonal Energy Efficiency Ratio. (SEER)
Use energy efficient ceiling fans either alone or with air conditioning. Ceiling fans do a great job of circulating air. When used with air conditioning, fans allow you to raise the thermostat and cut costs. Ceiling fans cool people, not rooms, so before you leave, turn off the ceiling fan.
Let a programmable thermostat “remember for you” to automatically adjust the indoor climate with your daily and weekend patterns to reduce cooling bills by up to 10 percent. You can come home to a comfortable house without wasting energy and creating pollution all day while you are at work.
Try to make your home airtight enough to increase your comfort, make your home quieter and cleaner and reduce your cooling costs up to 20 percent.
Cut your air conditioning load, and reduce pollution by planting leafy trees around your home and fixing reflective bricks on your roof.
Close blinds or shades on south-and west-facing windows during the day, or fix shading equipment to avoid heat build-up.
Turn off everything not in use: lights, TVs, computers. And use fluorescent bulbs, which provide bright, warm light while using at least two-thirds less energy, producing 70 percent less heat and lasting up to 10 times longer than incandescent bulbs.
Drive the car that gets better gas mileage whenever possible if you own more than one vehicle. If you drive 12,500 miles a year, switching 10 percent of your trips from a car that gets 20 miles per gallon to one that gets 30 mpg will save you more than £65 per year.
Carpool. The average U.S. commuter could save about £260 a year by sharing cars twice a week with two other people in a car that gets 20.1 mpg-assuming the three passengers share the cost of gas.
1.According to the passage, the thermostat is used to ________.
A.make rooms quieter B.control room temperature
C.turn off the air conditioner D.reduce room air pollution
2.We can conclude from the passage that the author probably discourages _________.
A.planting leafy trees around your home
B.turning off the ceiling fan before you leave your house
C.keeping your south-facing windows open during the day
D.using fluorescent bulbs instead of incandescent bulbs
3.According to the passage, you can save fuel by _______.
A.using energy-efficient ceiling fans
B.sharing cars with others on workdays
C.turning off everything not in use
D.reducing 10% of your car trips every year
One picture in the Wonder Book of knowledge I had as a little boy showed a man reading a book while floating in the Dead Sea. What a miracle! How would it feel to lie back in water so thick with salt that it was impossible to sink?
Fed by the Jordan River and smaller streams, the Dead Sea is the lowest point on the earth’s surface, and its water is ten times saltier than the Mediterranean. With evaporation its only outlet, salt and other minerals become super-concentrated.
Earlier this year, I drove down the long, steep hill to realize my dream. The shoreline was a broad area of bare salt-mud, but the water edge was far out of sight. Had somebody pulled the Dead Sea’s plug? I wondered. Eli Dior, an Israeli official, explained the problem: “The Dead Sea is drying up. Every year, the surface drops about one meter, and as the water level falls, shadow areas are left high and dry.”
Over the last half-century, the five neighboring countries have collectively diverted nearly all the water flowing into the Dead Sea to meet human and agriculture needs. Result: the Dead Sea is being emptied.
With population in the region set to double at least in the next 50 years, there is little hope of restoring the water being diverted for human consumption. No country has a drop to spare for the Dead Sea, where they know it will just evaporate. To dream of opening the dams and restoring natural balance is plainly unrealistic.
Yet one ambitious high-tech dream may turn out to be not only the salvation of the Dead Sea but also a ticket to peace around its shores. The “Red-Dead” is a proposed $5 billion project to bring sea water some 240 kilometers by pipeline and canal from the Red Sea to the Dead Sea. The Red-Dead may be the only solution, but even if the project is carried out successfully, the Dead Sea will be 10 to 20 meters lower than now and two thirds of its current size.
Whatever the future holds, the Dead Sea’s magical mix of sun, mud, sea and salt will surely survive. Many might complain that the Dead Sea is half empty—but for me the Dead sea will always be half full.
1.What’s the passage mainly about?
A.Dead Sea – miracle of the world.
B.Save the environment of the Dead Sea.
C.Slow shrinking of the Dead Sea.
D.Why is the Dead Sea so salty.
2.The shrinking of the Dead Sea is mainly caused by ________ according to the passage.
A.a severe reduction of the water flowing into the sea
B.rapid evaporation of the water in the Dead Sea area
C.the increasing quantity of water drawn from the sea
D.very low annual rainfall in the Dead Sea Area
3.Which of the following is right according to the passage?
A.With no outlet to any ocean, the Dead Sea has become by evaporation most dense waters on earth.
B.Though burdened with the growing population, the neighboring countries haven’t cut off the sources of the Dead Sea.
C.All the countries in the area will consider diverting less water from the Jordan River.
D.The Red-Dead Project has not only brought water to the Dead Sea, but peace to the area as well.
4.Which of the following statements will the author approve of?
A.If the Dead Sea dried up, great natural disasters would happen in the region.
B.The Dead Sea will not survive no matter what people do to save it.
C.The five neighboring countries should stop diverting water from the Jordan River.
D.Though the Dead Sea is shrinking gradually, it will not die.
