Honey from the African forest is not only a kind of natural sugar, it is also delicious. Most people, and many animals, like eating it. However, the only way for them to get that honey is to find a wild bees' nest and take the honey from it. Often, these nests are high up in trees, and it is difficult to find them. In parts of Africa, though, people and animals looking for honey have a strange and unexpected helper—a little bird called a honey guide.

    The honey guide does not actually like honey, but it does like the wax(蜂蜡) in the beehives(蜂房). The little bird cannot reach this wax, which is deep inside the bees' nest. So, when it finds a suitable nest, it looks for someone to help it. The honey guide gives a loud cry that attracts the attention of both passing animals and people. Once it has their attention, it flies through the forest, waiting from time to time for the curious animal or person as it leads them to the nest. When they finally arrive at the nest, the follower reaches in to get at the delicious honey as the bird patiently waits and watches. Some of the honey, and the wax, always falls to the ground, and this is when the honey guide takes its share.

    Scientists do not know why the honey guide likes eating the wax, but it is very determined in its efforts to get it. The birds seem to be able to smell wax from a long distance away. They will quickly arrive whenever a beekeeper is taking honey from his beehives, and will even enter churches when beeswax candles are being lit.

    Imagine that you're looking at your company-issued smartphone and you notice an e-mail from Linkedln: “These companies are looking for candidates like you!” You aren't necessarily searching for a job, but you're always open to opportunities, so out of curiosity, you click on the link. A few minutes later your boss appears at your desk. “We've noticed that you're spending more time on Linkedln lately, so I wanted to talk with you about your career and whether you're happy here,” she says. Uh-oh.

     It's an awkward scene. Attrition (损耗) has always been expensive for companies, but in many industries the cost of losing good workers is rising, owing to tight labor markets. Thus companies are making greater efforts to predict which workers are at high risk of leaving ,so that managers can try to stop them. Methods range from electronic monitor to well-designed analyses of employees' social media lives.

     Some of this work may be a reason to let employees to quit. In general, people leave their jobs because they don't like their boss, don't see opportunities for promotion or growth, or are offered a higher pay; these reasons have held steady for years.

    New research conducted by CEB, a Washington-based technology company, looks not just at why workers quit but also at when. “We've learned that what really affects people is their sense of how they're doing compared with other people in their peer group, or with where they thought they would be at a certain point in life, says Brian Kropp, who heads CEB's HR practice. “We've learned to focus on moments that allow people to make these comparisons.”

Technology also provides clues about which star employees might be eyeing the exit. Companies can tell whether employees using work computers or phones are spending time on (or even just opening e-mails from) career websites, and research shows that more firms are paying attention to these things. Large companies have also begun searching for badge swipes (浏览痕迹)—- employees' use of an ID to enter and exit the building or the parking garage—to identify patterns that suggest a worker may be interviewing for a job.

    A person can use all five senses while spending time with dolphins. We can see them play in the waves, hear them call, and feel their skin. Dolphins can sense you, too, but not in all the same ways. They have good eyesight, for example, but no sense of smell. Sensory biologists try to understand connections between animal behaviors and the senses. One team of these scientists recently made an unexpected discovery about certain dolphins.

    The researchers found that Guiana dolphins can detect electric fields, an ability that may help them find fish to eat. The secret to this newly found sense, say the scientists, is hidden in the dolphins' snouts (口鼻部).

    "We were really surprised to find this in the dolphin. Nobody had expected it," said Wolf Hanke, who led the new dolphin study.

    Hanke and his team suspected the dolphin's electro－sense might have something to do with small dimples (酒窝) on the animal's snout. "We thought they must have some functions," Hank said. To find out for certain, his team studied two Guiana dolphins.

    The scientists first studied the dimples of a 29－year－old dolphin that had died of natural causes. Under a microscope, the dimples looked familiar: they were similar to the sensors used by other animals to detect electric fields.

    Next, Hanke and his team tested a live dolphin, a 28－year－old named Paco, to see if he could recognize an electric field. They taught Paco to swim close to a device that could create a weak electric field in the water. Then the team taught Paco to swim away from the device if he detected any changes. When the scientists created an electric field, Paco swam away—showing that he knew something had changed. When there was no electric field, Paco stayed there. When Paco's snout was covered in plastic, he didn't react to the electric field.

    Paco's behavior told the scientists that the dolphin used his snout to detect the tiny electric field. "This is a major breakthrough," Peter Madsen, a sensory biologist, said.

    Taking good notes is a time-saving skill that will help you to become a better student in several ways. {#blank#}1{#/blank#} Second, your notes are excellent materials to refer to when you are studying for a test. Third, note-taking offers variety to your study time and helps you to hold your interest.

    You will want to take notes during classroom discussions and while reading a textbook or doing research for a report. {#blank#}2{#/blank#} Whenever or however you take notes, keep in mind that note-taking is a selective process. {#blank#}3{#/blank#}

    The following methods may work best for you.

    ● Read the text quickly to find the main facts and ideas in it.

    ● Carefully read the text and watch for words that can show main points and supporting facts.

    ● Write your notes in your own words.

    ● {#blank#}4{#/blank#}

    ● Note any questions or ideas you may have about what was said or written.

    As you take notes, you may want to use your own shorthand(速记). When you do, be sure that you understand your symbols and that you use them all the time. {#blank#}5{#/blank#}

A. Use words, not complete sentences.

B. There are three practical note-taking methods.

C. You must write your notes on separate paper.

D. Otherwise, you may not be able to read your notes later.

E. You will also want to develop your own method for taking notes.

F. That means you must first decide what is important enough to include in your notes.

G. First, the simple act of writing something down makes it easier for you to understand and remember it.

Smoking is harmful.But as soon as you quit the habit, everything will be OK,right?Wrong.

New research has found that even if you give up smoking, the damage it has done to your genes will stay there for a much longer time.In the research, a team of US scientists studied the blood of 16,000 people.Among them, some were smokers, some used to smoke, and the rest were non-smokers.Scientists compared their genes and found that more than 7,000 genes of smokers had changed--a number that is one-third of known human genes.

According to NBC News, both heart disease and cancer are caused by genetic changes.Some people may have had the changes when they were born, but most people get them in their day-to-day lives while doing things like smoking.

When you stop smoking, a lot of these genes will return to normal within five years.

This means your body is trying to heal (治愈) itself of the harmful effects of smoking.But the changes in some of the genes stay for longer.They can stay for as long as 30 years.It's almost like leaving a footprint on wet cement (水泥)—it will always be there,even when you've walked away and when the cement becomes dry.

Although the study results may make people unhappy, there is a bright side:the findings could help scientists invent medicine to treat genetic damage caused by smoking or find ways to tell which people have heart disease or cancer risks.