Elephants are able to know the difference between a man and a woman, and can tell an adult (成年人) from a child—all from the sound of a human voice. This is according to a study in which researchers played voice recordings to wild African elephants.

    The animals showed more fear when they heard the voices of adult Masai men. Usually Masai people hunt elephants, and this suggests that animals have grown to listen for and avoid them.

    Prof. Karen McComb and Dr Graeme Shannon from the University of Sussex led the study. They explained that in former research they had used similar experiments to show that elephants could tell—from the sound of a lion—whether the animal was a female (雌性) or a more dangerous male (雄性).

    Prof. McComb wanted to find out if the animals used their very sharp sense of hearing to recognize danger from humans.

    The scientists recorded Masai men, women and children saying, in their own language, “Look, look over there, a group of elephants are coming.” They also recorded Kamba men saying this phrase.

    Masai people often come across elephants, which can result in violent (暴力的) hunting. Kamba people, however, mainly feed on agriculture, which does not generally bring them into violent touch with the animals.

    When the team played recordings of these different voices through a hidden speaker, they found that elephant family groups showed more fear in response to the voice of a Masai man, than to a Kamba man's voice. And the adult male Masai voices caused far more violent response than the voices of women or boys.

    If you want to be a volunteer, you have to answer the following typical questions. Do you want to work with people, animals or machines? Do you want to work indoors or outdoors, directly serve people in need or serve people behind the scenes? Every year, thousands of people in the west offer volunteer service. Volunteering greatly strengthens the community because it helps the old, the young, the weak, the sick, and the disabled and the injured to solve problems.

    Volunteers usually help in many different ways. They may give people advice, offer friendship to the young, drive the elderly to church (if up to the driving age), advise kids against drugs, work as assistants in schools or nursing homes, raise funds, plant trees, help out in local libraries and do many other things. Volunteering can be a few hours a week or a few hours a month. Anybody who wants to serve people in need can become a volunteer.

    In fact, the art of volunteering is a process of both giving and receiving. Volunteering allows volunteers to meet new people, make new friends and mix with people from all walks of life. Volunteering is an excellent way to experiment and try out new techniques and skills, discover your individual talents and explore career choice. Being a volunteer will take you on a wonderful journey and help you learn more than what you can get from books.

    Wilbur and Orville Wright were the two youngest sons of Bishop Milton Wright, Wilbur was born on a farm near Millville and Orville was born in August in the house the family would come to occupy for more than 40 years in Dayton.

    Orville would discover in later years that he and Wilbur's first interests in flight began when they were children, with powered rubber-band-helicopter toys that their father would bring home for them from trips around the country. Orville and Wilbur would build duplicates（复制品）of these toys and bounce them off the ceiling. They were just crazy about these things for the reasons that they did not yet understand.

    Both boys loved to solve problems that seemed difficult to others. The more difficult the problem was, the more they saw it as a challenge. Exploring the unknown was such a joy for then that Orville once said, "I can remember when Wilbur and I could hardly wait for the morning to come to get at something that interested us. That's happiness."

    Putting their gift to work, the boys entered the printing business soon after high school. Orville designed and then built a printing press（印刷机）for this enterprise. At first, they did contract printing for other people, and soon one of their customers during the early 1890s was Father Milton's church. They also tried the newspaper business, and although their two newspapers, the West Side News and The Evening Item were considered to be of high quality, Dayton already had daily newspapers, so the Wrights soon returned to contract printing.

    Branching out into other areas, they also opened a bicycle business. Bicycling was the fastest growing sport in the country at that time, and their repair shop soon led them into building bicycles of their own design, often with tools of their own construction, such as the lathe（车床）driven by a one-cylinder gasoline engine built by Orville. The bicycle shop would provide the livelihood（生计）that would allow them to carry out their experiments on airplanes.

    The 2019 Beijing Horticultural Expo, the largest of its kind, has chosen the theme "Live Green, Live Better". The expo, opened on April 29 in Yanqing District of Beijing, is scheduled to last for 162 days until October 7.

    Tickets available

    *Standard day ticket

    *Designated day ticket

    *Discounted ticket

    *Group ticket

    Designated days

    *Labor Day holiday (May 1-4)

    *Dragon Boat Festival holiday (June 7-9)

    *Mid-Autumn Festival holiday (Sept 13-15)

    *National Day holiday (Oct 1-7)

    Tickets prices

    *Standard day ticket: 120 yuan

    *Ordinary designated day ticket: 160 yuan

    *Discounted standard day ticket: 80 yuan

    *Discounted designated day ticket: 120 yuan

    Tickets are free for children under the age of six or shorter than 130 centimeters. Discounted tickets are available for those with disabilities, seniors (people aged at 60 or above), children, students and PLA soldiers.

    Where to buy

    Visitors can buy or book tickets from two online agents, seven travel agencies, or three event channels—the event WeChat account, the event app or Onsite ticket kiosks.

Opening hours

Requirements

    Buying tickets for Expo 2019 Beijing requires real-name registration, and all visitors are required to input information from their ID cards (or valid passports, mainland travel permits for Hong Kong and Macao residents, and mainland travel permits for Taiwan residents) to buy or book tickets online.

    Parents who help their children with homework may actually be bringing down their school grades. Other forms of parental involvement, including volunteering at school and observing a child's class, also fail to help, according to the most recent study on the topic.

    The findings challenge a key principle of modern parenting(养育子女) where schools expect them to act as partners in their children's education. Previous generations concentrated on getting children to school on time, fed, dressed and ready to learn.

    Keith Robinson, the author of the study, said, "I really don't know if the public is ready for this but there are some ways parents can be involved in their kids' education that leads to declines in their academic performance. One of the things that were consistently negative was parents' help with homework." Robinson suggested that may be because parents themselves struggle to understand the tasks. "They may either not remember the material their kids are studying now, or in some cases never learn it themselves, but they're still offering advice."

    Robinson assessed parental involvement performance and found one of the most damaging things a parent could do was to punish their children for poor marks. In general, about 20% of parental involvement was positive, about 45% negative and the rest statistically insignificant.

    Common sense suggests it was a good thing for parents to get involved because "children with good academic success do have involved parents", admitted Robinson. But he argued that this did not prove parental involvement was the root cause of that success. "A big surprise was that Asian American parents whose kids are doing so well in school hardly involved. They took a more reasonable approach, conveying to their children how success at school could improve their lives."

    What is a lifestyle and how is that different from a life? A lifestyle is about brand names and buying identity or fame. Lifestyle gives a false sense of peace and acceptability that comes from others recognizing what you've bought into (as well as bought). If your car, clothes, and home are expensive, you're sophisticated (世故的) and stylish. If you have the right kind of job or go to the right social gatherings, then you receive the insincere approval of others. This means that your self-esteem (自尊) is always at the mercy of others, with no appreciation of you as an individual.

    A life, on the other hand, is very different. A life is what you lead when you know what matters most to you. It is very simple and comes from being connected to what you know is important and being willing to put that first, no matter what others may think. When you create a life vs. a lifestyle, your self-esteem comes from what's inside you, not what others think about you.

    Lifestyle is expensive financially and personally, because it costs a great deal to keep up appearances and do what you think is socially acceptable. A life is not expensive. Rather than using personal or financial resources, a life generates energy and staying power. It's about liberating yourself from the mindless consumption that society expects. It is about making the choices that are in line with your values, instead of using up your bank account or energy for no heart-driven reason.

    How can you make the change? Understand the difference between a life and a lifestyle. Analyze your current lifestyle to see what is costing you in money, time, stress, and energy to maintain it. Let go and make room for what is really important to you, what supports you and brings you joy. Remember who you are from within, not what you own!