Cold weather has a great effect on how our minds and our bodies work. Maybe that is why there are so many expressions that use the word cold. For centuries, the body's blood has been linked closely with the emotions. People who show no human emotions or feelings, for example, are said to be cold –blooded. Cold –blooded people act in merciless ways. They may do cruel things to others, and not by accident. For example, a newspaper says the police are searching for a cold-blooded killer. The killer murdered someone, not in self-defense. He seemed to kill with no emotion.

    Cold can affect other parts of the body, the feet, for example. Heavy socks can warm your feet, if your feet are really cold. But there is an expression—to get cold feet –that has nothing to do with cold or your feet. The expression means being afraid to do something you had decided to do. For example, you agree to be president of an organization. But then you learn that all the other officers have given up the position. All the work of the organization will be your responsibility. You are likely to get cold feet about being president when you understand the situation.

    Cold can also affect your shoulder. You give someone the cold shoulder when you refuse to speak to them. You treat them in a distant, cold way. The expression probably comes from the physical act of turning your back toward someone, instead of speaking to him face-to-face. You may give a cold shoulder to a friend who has not kept a promise he made to you. Or, to someone who has lied about you to others.

    A cold fish is not a fish. It is a person. But it is a person who is unfriendly, unemotional and shows no love or warmth. A cold fish does not offer much of himself to anyone.

    Out in the cold is an expression often heard. It means not getting something that everybody else got. A person might say that everybody but him got a pay raise. He was left out in the cold. And it is not a pleasant place to be.

    In 1812, the year Charles Dickens was born, there were 66 novels published in Britain. People had been writing novels for a century—most experts date the first novel to Robinson Crusoe in 1719—but nobody wanted to do it professionally. The steam-powered printing press was still in its early stages; the literacy（识字） rate in England was under 50%. Many works of fiction appeared without the names of the authors, often with something like “By a lady.”Novels, for the most part, were looked upon as silly, immoral, or just plain bad.

    In 1870, when Dickens died, the world mourned him as its first professional writer and publisher, famous and beloved, who had led an explosion in both the publication of novels and their readership and whose characters — from Oliver Twist to Tiny Tim— were held up as moral touchstones. Today Dickens' greatness is unchallenged. Removing him from the pantheon（名人堂） of English literature would make about as much sense as the Louvre selling off the Mona Lisa.

    How did Dickens get to the top? For all the feelings readers attach to stories, literature is a numbers game, and the test of time is extremely difficult to pass. Some 60,000 novels were published during the Victorian age, from 1837 to1901; today a casual reader might be able to name a half-dozen of them. It's partly true that Dickens' style of writing attracted audiences from all walks of life. It's partly that his writings rode a wave of social, political and scientific progress. But it's also that he rewrote the culture of literature and put himself at the center. No one will ever know what mix of talent, ambition, energy and luck made Dickens such a singular writer. But as the 200th anniversary of his birth approaches, it is possible — and important for our own culture—to understand how he made himself a lasting one.

    No one knows how much money Dr. Lyle Tullis gave away to students. I was his colleague for nearly a decade and I never stopped being amazed at his generosity. Our college has a program of providing cross-cultural experiences for students. Lots of students take advantage of summer experiences oversea. I discovered that no group left for overseas without some of its members receiving financial help from Dr. Tullis.

    It wasn't that he made a lot of money. For one thing, he taught in a church-run school. There, his salary (薪水) was half of what those people earned in a tax-supported school.

    Other colleagues occasionally complained about the low pay. Not Lyle Tullis. Occasionally some professors would leave our campus for a better-paid position. They told me they did so because, with better pay, they could provide for their families.

    The size of Lyle Tullis' paycheck never seemed to be the most important thing to him. I realized that one day when I was thanking him for helping a student, his eyes shone as he said to me, "I've got so much money that I don't know what to do with it. So, I just give it away."

    Most people wouldn't have thought that way. Dr. Tullis drove one of the oldest cars on campus. It was even older than almost any of the students' cars. His home, while comfortable, was not fancy at all. But Lyle Tullis lived with the feeling that he had so much money that he needed to give it away.

    He was one of the favorite on campus. Cynics (愤世嫉俗) might say he bought fame. But they would misunderstand. Lyle wanted to devote his life, all of it, to helping others.

    Gardeners such as Prince Charles who claim that talking to plants encourages them to grow have long been seen as a little silly. But scientists have discovered evidence which suggests the Royal may actually be right and they could be listening to him. Biologists at Tel Aviv University in Israel have found that flowers can act as a plant's "ears" to help them detect the sound of approaching insects.

    When the researchers played recordings of flying bees to evening primrose flowers, within three minutes the sugar concentrations in the nectar (花蜜) of its flowers increased. The fluid, produced to attract pollinating (授粉) insects, was on average 20 percent higher in flowers exposed to the buzz compared to those left in silence or exposed to higher pitched sounds. Professor Lilach Hadany, who led the study, said: "Our results document for the first time that plants can rapidly respond to pollinator sounds in an ecologically relevant way."

    However, Prof Hadany said a plant's ability to respond to pollinators may be weakened in city environments or beside a busy road. While plants require water, sunlight and the right temperature to grow, it is widely believed they do not have senses in the way animals do.

    But the study, published on the open-science website BioRxiv, suggests the efforts of gardeners who talk to their plants may not be in vain. "Plants' ability to hear has implications well beyond pollination—plants could potentially hear and respond to herbivores, other animals, the elements, and possibly other plants," Prof Hadany added.

    A month-long experiment conducted by the Royal Horticultural Society in 2009 found female voices appear to speed up the growth of tomatoes. The research offers a possible explanation — women's voices were at the right frequency for the plants to hear.

    For thousands of years, people have known that the best way to understand a concept is to explain it to someone else. "While we teach, we learn," said Roman philosopher Seneca. Now scientists are bringing this ancient wisdom up to date. They're documenting why teaching is such a fruitful w ay to learn, and designing creative ways for young people to take part in instruction.

    Researchers have found that students who sign up to tutor others work harder to understand the material, recall it more accurately and apply it more effectively. Student teachers score higher on tests than pupils who're learning only for their own sake. But how can children, still learning themselves, teach others? One answer: They can tutor younger kids. Some studies have found that first-born children are more intelligent than their later-born siblings(兄弟姐妹). This suggests their higher IQs result from the time they spend teaching their siblings. Now educators are experimenting with ways to apply this model to academic subjects. They arrange college undergraduates to teach computer science to high school students, who in turn instruct middle school students on the topic.

    But the most cutting-edge tool under development is the "teachable agent" — a computerized character who learns, tries, makes mistakes and asks questions just like a real-world pupil.

    Computer scientists have created an animated(动画的)figure called Betty's Brain, who has been "taught" about environmental science by hundreds of middle school students. Student teachers are inspired to help Betty master certain materials. While preparing to teach, they organize their know ledge and improve their own understanding. And as they explain the information to it, they identify problems in their own thinking.

    Feedback from the teachable agents further improves the tutors' learning. The agents' questions forces student tutors to think and explain the materials in different ways, and watching the agent solve problems allow s them to see their know ledge put into action.

    Above all, it's the emotions one experiences in teaching that improve learning. Student tutors feel upset when their teachable agents fail, but happy when these virtual pupils succeed as they develop pride and satisfaction from someone else's accomplishment.

    Chinese media and Internet users on Monday decried（谴责）a lack of morals in society after a child was struck twice by two different trucks and left bleeding on the road as more than a dozen bystanders did nothing to help the seriously injured girl.

    The incident, captured by a surveillance camera and aired by Southern Television Guangdong (TVS), showed the two-year-old girl was knocked down and run over by a white truck on a narrow market street on the afternoon of Oct. 13, in Foshan City of Guangdong Province.

    The driver fled the scene of the accident, leaving the girl to bleed on the sidewalk. Over the next six minutes, more than a dozen people walked by the girl, yet not one individual did anything to help her. The girl was then hit a second time by another van before an elderly trash collector came to her aid and brought the attention of the girl's mother, according to the video and eyewitnesses.

    Doctors said that the girl, who was put on life support after being hospitalized, remains in a deep coma. The girl's parents, who are migrants living in the city, are now with her.

    Police said the drivers of both vehicles have been arrested. However, the apathy(冷漠) of the bystanders shown in the video has shocked the public, and people are questioning the morality of society.

    High moral standards were once considered as national pride in China where individuals known for selflessly helping others were adored（崇拜） by the public.

    But in recent years, the perception（观念）of a decline of morals has become a hot topic as profit and materialism are perceived to be affecting society's values.

    On Sept. 2. an 88-year-old man in central China collapsed, his face striking the pavement. Yet, no one came to his aid, and he ended up choking to death on the blood from his nose.

    Some have linked the absence of good Samaritans (模范人物)to a previous case in which a man trying to help an elderly woman who fell was accused of harming her.

    A strong chorus of opinion on the Internet says laws should exempt（免除）Samaritans from liability（责任）, yet laws themselves cannot solve society's morality dilemma.

    Cao Lin, a China Youth Daily commentator, said in a signed article published on Monday that the worry of liability should not be an excuse for not helping, and this case exposes the decline of humanity in Chinese society.