Scientists are debating how to limit their newly-discovered power to change genetic structure (结构). Scientists already modify the genes (基因) of farm animals and agricultural plants to make them more productive or stronger. But now they can also change genes in wild animals and plants. These genes would continue into later generations. For example, it may be possible for scientists to remove from existence the kind of mosquitoes, small flying insects, that carry the Zika virus. They might also be able to permanently remove species (物种) of plants and animals that are damaging to other species.

    In a report published last week, the U. S. National Academies of Sciences, Engineering and Medicine (NAS) said it supports continued research on this kind of gene control. But it warned that it is not possible to know what will happen when these changed plants and animals are released (释放) into the wild.

    Sixteen biologists, ethicists (伦理学家) and policymakers are on an NAS committee that is examining the issue. They say that there is value to the new technology. But, they say, there is not enough evidence to support the release of modified organisms (生物体) from the laboratory into nature.

    Many people would support stopping mosquitoes and rats from carrying diseases. But scientists say we must understand the possible scientific, ethical, legal and social results of such action before we decide whether to take it. Gene modification is spread through reproduction (繁殖).

    Changed genes will continue to spread as long as an animal or plant continues to reproduce. They cannot be limited to a farm or kept within a country's borders. Scientists are wondering what may happen if a modified organism mates with another species. They are not yet sure how the modified genes would affect the other species. It is possible that those genes could harm those creatures or even lead to their disappearance from our planet.

    No one can deny that buttons are an important device. Whenever we see a button, we are eager to press it because we know something will happen. This is true in most cases, for example on a doorbell and on the “on/off” button on the TV. But some buttons are actually fake, like the “close” button on a lift.

    Many people are in the habit of pressing the “close” button because they don't have the patience to wait for the lift doors to shut. But lifts' “close” buttons are a complete scam (骗局), at least in the US － the doors will not close any faster no matter how hard you press.

    It started in the 1990s when the Americans with Disabilities Act was passed in the US, making sure that all lifts stayed open long enough so that people with disabilities could enter. Only US firefighters and repairmen can use the buttons to speed up the door-closing process if they have a code or special keys.

    But to normal lift riders, the buttons aren't completely useless. According to psychologists, fake buttons can actually make you feel better by offering you a sense of control.

     “Perceived (能够感知的) control is very important. It reduces stress and increases well-being,” Ellen J. Langer, a psychology professor, said, “ having a lack of control is associated with depression.”

    Experts have revealed that a lot of buttons that don't do anything exist in our lives for this same purpose. For example, many offices in the US have fake thermostats (温度调节器) because people tend to feel better when they think they can control the temperature in their workspace.

    But psychologists found it interesting that even when people are aware of these little “white lies”, they still continue to push fake buttons because as long as the doors eventually close, it is considered to be worth the effort.

     “That habit is here to stay,” John Kounios, a psychology professor, said. “Even though I have real doubts about the traffic light buttons, I always press them. After all, I've got nothing else to do while waiting. So why not press the button in the hope that this one will work?”

    Across Britain, burnt toast will be served to mothers in bed  this morning as older sons and daughters to deliver their supermarket bunches of flowers, But, according to a new study, we should be placing a higher value on motherhood all year.

    Mothers have long known that their home worked was just heavy as paid work. Now, the new study has shown that if they were paid for their parental labors, they would earn as much as￡172,000 a year.

    The study looked at the range of jobs mothers do, as well as the hours they are working, to determine the figure. This would make their yearly income ￡30, 000 more than the Prime Minister earns.

    By analyzing the numbers, it found the average mother works 119 hours a week,40 of which would usually be paid at a standard rate 79 hours as overtime. After questioning 1,000 mothers with children under 18,it found that ,on most days, mums started their routine work at 7am and finished at around 11pm.

    To calculate just how much mothers would earn from that labor, it suggested some of the roles that mums could take on, including housekeeper, part-time lawyer, personal trainer and entertainer. Being a part-time lawyer, at ￡48.98 an hour, would prove to be the most profitable of the “mum jibs”, with psychologist（心理学家）a close second.

    It also asked mothers about the challenges they face, with 80 percent making emotional（情感的）emand as the hardest thing about motherhood.

Over a third of mums felt they needed more training and around half said they missed going out with friends.

    The study shoes mothers matter all year long and not just on, Mother's Day. The emotional, physical and mental energy mothers devote to their children can be never-ending, but children are also sources of great joy and happiness. Investing（投入）in time for parenting and raising relationships is money well spent.

    Doctors in hospital emergency rooms often see accidental poisonings. A frightened parent arrives with a child who swallowed a cleaning liquid. Or perhaps the harmful substance is a medicine. Or it might be a chemical product meant to kill insects. These are common causes of accidental poisoning.

    In cases like this, seek medical help as soon as possible. Save the container of whatever caused the poisoning. And look on the container for information about anything that stops the effects of the poison. Save anything expelled from the mouth of the victim. That way, doctors can examine it.

    Millions of people know a way to save a person who is choking on something trapped in the throat. The method is commonly known as the Heimlich Maneuver or abdominal thrusts(腹部按压), which you can do by getting directly behind a sitting or standing person. Put your arms around the victim's waist. Close one hand to form a ball. Place it over the upper part of the stomach, below the ribs. Place the other hand on top. Then push forcefully inward and upward. Repeat the abdominal thrusts until the object is expelled from the mouth. For someone who is pregnant or very fat, place your hands a little higher than with normal abdominal thrusts.

    Red Cross experts say taking these steps can save many lives. But they also warn that abdominal thrusts are not for people who have almost drowned. They say use of the method could delay other ways to re-start breathing in the victim. Abdominal thrusts should be used only in cases where a near-drowning victim is choking on an object.

    To learn more about first aid, ask a hospital or organization like a Red Cross or Red Crescent Society for information. There may be training classes offered in your area.

    A long-term American study shows the importance of early education for poor children. The study is known as the Abecedarian Project. It involved more than one-hundred young children from poor families in North Carolina.

    Half of the children attended an all-day program at a high-quality child-care center. The center offered educational, health and social programs. Children took part in games and activities to increase their thinking and language skills and social and emotional development. The program also included health foods for the children.

    The children attended the program from when they were a few weeks old until the age of five years. The other group of children did not attend the child-care center. After the age of five, both groups attended public school.

    Researchers compared the two groups of children. When they were babies, both groups had similar results in tests for mental and physical skills. However, from the age of eighteen months, the children in the educational child-care program did much better in tests.

    The researchers tested the children again when they were twelve and fifteen years old. The tests found that the children who had been in the child-care center continued to have higher average test results. These children did much better on tests of reading and mathematics.

    A few years ago, organizers of the Abecedarian Project tested the students again. At the time, each student was twenty-one years old. They were tested for thinking and educational ability, employment, parenting and social skills. The researchers found that the young adults who had the early education still did better in reading and mathematics tests. They were more than two times as likely to be attending college or to have completed college. In addition, the children who received early education were older on average, when their first child was born.

    The study offers more evidence that learning during the first months and years of life is important for all later development.

    The researchers of the Abecedarian Project believe their study shows a need for lawmakers to spend money on public early education. They believe these kinds of programs could reduce the number of children who do not complete school and are unemployed.

    Milton Hershey was born near the small village of Derry Church, Pennsylvania, in 1857. He only attended school through the fourth grade; at that point, he was apprenticed(做学徒) to a printer in a nearby town. After a while, he left the printing business and was apprenticed to a Lancaster, Pennsylvania candy maker. And at the age of eighteen, he opened his own candy store in Philadelphia. In spite of his talents as a candy maker, the shop failed after six years.

    After the failure of his Philadelphia store, Milton headed for Denver, where he learned the art of making caramels(焦糖). Then in Denver, Milton once again attempted to open his own candy-making businesses, in Chicago, New Orleans, and New York City. Finally, in 1886, he went to Lancaster, Pennsylvania, where he raised the money necessary to try again. This company— the Lancaster Caramel Company—established Milton's reputation as a master candy maker.

    In 1893, Milton attended the Chicago International Exposition, where he saw a display of German chocolate-making implements. Fascinated by the equipment, he purchased it for his Lancaster candy factory and began producing chocolate, which he used for coating his caramels. By the next year, production had grown to include cocoa, sweet chocolate, and baking chocolate. The Hershey Chocolate company was born in 1894 as a subsidiary(子公司) of the Lancaster Caramel Company. Six years later, Milton sold the caramel company, but reserved the rights, and the equipment, to make chocolate. He believed that a large market of chocolate consumers was waiting for someone to produce reasonably priced candy. He was right.

    Milton Hershey returned to the village where he had been born, in the heart of dairy country, and opened his chocolate manufacturing plant. With access to all the fresh milk he needed, he began producing the finest milk chocolate. The plant that opened in a small Pennsylvania village in 1905 is today the largest chocolate factory in the world. The sweets created at this facility are favorites around the world.

    The area where the factory is located is now known as Hershey, Pennsylvania. Within the first decades of its existence, the town of Hershey thrived, as did the chocolate business. A bank, a school, churches, a department store, even a park and a trolley system all appeared in short order; the town soon even had a zoo. Today, a visit to the area reveals the Hershey Medical Center, Milton Hershey School, and Hershey's Chocolate World—a theme park where visitors are greeted by a giant Reeses Peanut Butter Cup. All of these things— and a huge number of happy chocolate lovers—were made possible because a caramel maker visited the Chicago Exposition of 1893!