4 . The connection between people and plants has long been the subject of scientific research. Recent studies have found positive effects. A study conducted in Youngstown，Ohio，for example, discovered that greener areas of the city experienced less crime. In another，employees were shown to be 15% more productive when their workplaces were decorated with houseplants.

The engineers at the Massachusetts Institute of Technology(MIT)have taken it a step further changing the actual composition of plants in order to get them to perform diverse，even unusual functions. These include plants that have sensors printed onto their leaves to show when they’re short of water and a plant that can detect harmful chemicals in groundwater. ＂We’re thinking about how we can engineer plants to replace functions of the things that we use every day,＂explained Michael Strano, a professor of chemical engineering at MIT.

One of his latest projects has been to make plants glow(发光)in experiments using some common vegetables. Strano’s team found that they could create a faint light for three-and-a-half hours. The light，about one-thousandth of the amount needed to read by，is just a start. The technology, Strano said, could one day be used to light the rooms or even to turn trees into self-powered street lamps.

In the future，the team hopes to develop a version of the technology that can be sprayed onto plant leaves in a one-off treatment that would last the plant’s lifetime. The engineers are also trying to develop an on and off＂switch＂where the glow would fade when exposed to daylight.

Lighting accounts for about 7% of the total electricity consumed in the US. Since lighting is often far removed from the power source(电源)-such as the distance from a power plant to street lamps on a remote highway-a lot of energy is lost during transmission(传输).Glowing plants could reduce this distance and therefore help save energy.

5 . Race walking shares many fitness benefits with running, research shows, while most likely contributing to fewer injuries. It does, however, have its own problem.

Race walkers are conditioned athletes. The longest track and field event at the Summer Olympics is the 50-kilometer race walk, which is about five miles longer than the marathon. But the sport’s rules require that a race walker’s knees stay straight through most of the leg swing and one foot remain in contact (接触) with the ground at all times. It’s this strange form that makes race walking such an attractive activity, however, says Jaclyn Norberg, an assistant professor of exercise science at Salem State University in Salem, Mass.

Like running, race walking is physically demanding, she says, According to most calculations, race walkers moving at a pace of six miles per hour would burn about 800 calories(卡路里) per hour, which is approximately twice as many as they would burn walking, although fewer than running, which would probably burn about 1,000 or more calories per hour.

However, race walking does not pound the body as much as running does, Dr. Norberg says. According to her research, runners hit the ground with as much as four times their body weight per step, while race walkers, who do not leave the ground, create only about 1.4 times their body weight with each step.

As a result, she says, some of the injuries associated with running, such as runner’s knee, are uncommon among race walkers. But the sport’s strange form does place considerable stress on the ankles and hips, so people with a history of such injuries might want to be cautious in adopting the sport. In fact, anyone wishing to try race walking should probably first consult a coach or experienced racer to learn proper technique, she says. It takes some practice.

The Meredith family lived in a small community. As the economy was in decline, some people in the town had lost their jobs. Many of their families were struggling to make ends meet. People were trying to help each other meet the challenges.

Mrs. Meredith was a most kind and thoughtful woman. She spent a great deal of time visiting the poor. She knew they had problems, and they needed all kinds of help. When she had time, she would bring food and medicine to them.

One morning she told her children about a family she had visited the day before. There was a man sick in bed, his wife, who took care of him and could not go out to work, and their little boy. The little boy -his name was Bernard-had interested her very much.

“I wish you could see him,” she said to her own children, John, Harry, and Clara. “He is such a help to his mother. He wants very much to earn some money, but I don't see what he can do.”

After their mother left the room, the children sat thinking about Bernard. “I wish we could help him to earn money,” said Clara. “His family is suffering so much.”

“So do I,” said Harry. “We really should do something to assist them.”

For some moments, John said nothing, but, suddenly, he sprang to his feet and cried, “I have a great idea! I have a solution that we can all help accomplish(完成).”

The other children also jumped up all attention. When John had an idea, it was sure to be a good one. “I tell you what we can do,” said John. “You know that big box of corn Uncle John sent us? Well, we can make popcorn(爆米花), and put it into paper bags, and Bernard can take it around to the houses and sell it.”

7 . Some individuals are born with a gift for public speaking.    1    Do you want to be a good public speaker? Here are some principles you must master.

People want to listen to someone who is interesting, relaxed and comfortable. Too often when you stand up to give a speech, you focus on the “public”at the expense of the “speaking. ”       2     Focus on the speaking. Talk directly to your audience, be yourself and make a connection.

Even the most successful public speaker will make mistakes. Yet, the only one who cares about any mistake is the one who is speaking. People’s attention wanders constantly. In fact,most people only absorb about 20 percent of a speaker’s message. So, don’t stop speaking when you make a mistake unless it’s a truly serious one.    3    

Your goal is not to be a perfect public speaker.    4    And like everything else in life, that takes practice. Remember, even world champion athletes practice their skills on a consistent basis.

    5    It’s rare to hear someone say, “I wish that speaker had spoken longer. “On the other hand, you probably can’t count the times that you’ve thought, “I’m glad that talk is over. It seemed to go on forever! “So surprise your audience. Always make your presentation just a bit shorter than anticipated. It’s better to leave your listeners wishing for more than shifting restlessly in their seats waiting for your speech finally to end.

8 . Imagine a child standing on a diving board four feet high and asking himself the question: “Should I jump?” This is what motivation or the lack of it can do. Motivation and goal setting are the two sides of same coin.     1     Like the child on the diving board, you will stay undecided.

    2     More than that, how should you stay motivated to achieve the goal? First, you need to evaluate yourself, your values, your strengths, your weaknesses, your achievements, your desires, etc. Only then should you set your goals.

You also need to judge the quality and depth of your motivation. This is quite important, because it is directly related to your commitment. There are times when your heart is not in your work.     3     So, slow down and think what you really want to do at that moment. Clarity(清晰) of thoughts can help you move forward.

Another way of setting realistic goals is to analyze your short and long term objectives, keeping in mind your beliefs, values and strengths. Remember that goals are flexible.     4     They also need to be measurable. You must keep these points in mind while setting your goals.

Your personal circumstances are equally important. For example, you may want to be a pilot but can’t become one because your eyesight is not good enough.     5    You should reassess your goals, and motivate yourself to set a fresh goal.

You will surely need to overcome some difficulties, some planned, but most unplanned. You cannot overcome them without ample motivation. Make sure that you plan for these difficulties at the time of setting your goals.

10 . When you were trying to figure out what to buy for the environmentalist on your holiday list, fur probably didn’t cross your mind. But some ecologists and fashion (时装)enthusiasts are trying to bring back the market for fur made from nutria(海狸鼠).

Unusual fashion shows in New Orleans and Brooklyn have showcased nutria fur made into clothes in different styles. “It sounds crazy to talk about guilt-free fur-unless you understand that the nutria are destroying vast wetlands every year”, says Cree McCree, project director of Righteous Fur.

Scientists in Louisiana were so concerned that they decided to pay hunters $5 a tail. Some of the fur ends up in the fashion shows like the one in Brooklyn last month.

Nutria were brought there from Argentina by fur farmers and let go into the wild. “The ecosystem down there can’t handle this non-native species(物种).It’s destroying the environment. It’s them or us.” says Michael Massimi, an expert in this field.

The fur trade kept nutria in check for decades，but when the market for nutria collapsed in the late 1980s，the cat-sized animals multiplied like crazy.

Biologist Edmond Mouton runs the nutria control program for Louisiana. He says it’s not easy to convince people that nutria fur is green, but he has no doubt about it. Hunters bring in more than 300,000 nutria tails a year, so part of Mouton’s job these days is trying to promote fur.

Then there’s Righteous Fur and its unusual fashion. Model Paige Morgan says，”To give people a guilt-free option that they can wear without someone throwing paint on them-I think that’s going to be a massive thing, at least here in New York.” Designer Jennifer Anderson admits it took her a while to come around to the opinion that using nutria fur for her creations is morally acceptable. She is trying to come up with a label to attach to nutria fashions to show it is eco-friendly.