Imagine you're standing in line to buy a snack at a store. You step up to the counter and the cashier scans your food. Next, you have to pay. but instead of scanning a QR Code（二维码）with your smart phone, you just hold out your hand so the cashier can scan your fingerprint. Or, a camera scans your face, your eyes or even your ear.

    Now, this type of technology might not be far away. As technology companies move away from the traditional password, biometric（生物特征识别的）security, which includes fingerprint, face and voice ID, is becoming increasingly popular.

    In 2013, Apple introduced the iPhone 5s, one of the first smart phones with a fingerprint scanner. Since then, using one's fingerprint to unlock a phone and make mobile payments has become commonplace, bringing convenience to our lives. And since 2016, Samsung has featured eye-scanning technology in its top smart phones, while Apple's new iphone X can even scan a user's face. But despite its popularity, experts warn that biometrics might not be as secure as we imagine. “Biometrics is ideally good in practice, not so much,” said John Michener, a biometrics expert.

    When introducing the new iPhone's face ID feature, Phil Schiller, Apple's senior vice-president, said. “The chance that a random person in the population could look at your iPhones X and unlock it with their face is about one in a million.” But it's already been done. In a video posted on a community website Reddit, two brothers showed how they were each able to unlock the same iPhone X using their own face. And they aren't even twins.

    “We may expect too much from biometrics,” Anil Jain, a computer science professor at Michigan State University, told CBS News. “No security systems are perfect.”

    Earlier last year, Jain found a way to trick biometric security. Using a printed copy of a thumbprint, she was able to unlock a dead person's smart phone for the police, according to a tech website Splinter. “It's good to see biometrics being used more,” Jain told CBS News, “because it adds another factor for security. But using multiple security measures is the best defense.”

    The fried foods, salty snacks and meat are major foods of the Western diet, which account for about 30 percent of heart attack risk across the world. Meanwhile, a diet rich in fruits and vegetables, the so called "Prudent" diet, can lower the risk of heart attack, according to a study.

    The research which looked at dietary habits in 52 countries, found people who ate a Western diet had a 35 percent greater risk of having a heart attack, compared to those who ate little or no fried foods and meat. Those who followed a "Prudent" diet had a 30 percent lower risk of heart attack, compared to those who eat little fruits and vegetables.

    The authors also looked at an "Oriental" diet, rich in tofu, soy and other sauces (酱类), and found it did not increase or decrease the risk of a heart attack.

    Previous studies have reached similar conclusions about the "Prudent" and Western diet in the United States and Europe, but did not include the Oriental pattern of eating. While some food of the Oriental diet may protect against heart trouble, the higher sodium (钠)content of sauces counter(抵消) that benefit.

    "This study indicates that the same relationships that are observed in Western countries exist in different regions of the world, "a professor of medicine at McMaster University said.

    Canadian researchers analyzed risk factors in food choices and the risk of heart attack in about 16, 000 people in 52 countries. Almost 6, 000 people had heart attacks, while the rest had no heart disease.

    Five million people visit Grand Canyon in the US every year. For the purpose of helping project Grand Canyon for your fellow visitors and future generations, please follow the guidelines below.

   Camping

    To project the park, camping is allowed only within permitted campgrounds. Permits are required for overnight camping at the North Rim. Advance booking can be received by mail. Please write: Information Center, P.O. Box 129, Grand Canyon, AZ 86023

    Fires

    Because of the extreme fire danger, campfires are not allowed except at Mather and Desert View campgrounds. Collection of firewood is not allowed either.

    Hiking

    Please stay on permitted paths. Otherwise you may destroy desert plants. Pack out what you pack in, so you leave no signs of your visit. It is important to keep in mind that you are in a national park where wildlife exists.

    Weather

    The weather at Grand Canyon can change very quickly. With so much rock, lightning causes a particular danger during sudden summer storms. These storms also frequently bring floods inside valleys, a danger to hikers. Watch the skies and check daily weather reports.

    Wildlife

    Do not feed park wildlife. There have been a few cases at Grand Canyon National Park where deer were purposely shot because they ate plastic bags that left them sick and weak. Hungry deer can be danger and have kicked and bitten visitors at Grand Canyon. Some other animals will also beg and bite. For your own safety and the well-being of the animals, please do not feed wildlife, no matter how gentle they may appear.

    A young woman sits alone in café sipping tea and reading a book. She pauses briefly to write in a nearby notepad before showing her words to a passing café waiter: "Where are the toilets please?" This is a familiar scene in Tokyo's so-called "silent cafes", where customers are not allowed to speak, and only communicate by writing in notepads.

    The concept rises by a desire to be alone among young Japanese, a situation brought by economic uncertainly, a shift in traditional family support structures and the growing social isolation. The phenomenon is not limited to coffee shops but covers everything from silent discos, where participants dance alone wearing wireless headphones connected to the DJ, to products such as small desk tents designed for conversation-free privacy in the office. One Kyoto company even offers single women the opportunity to have a "one woman wedding" – a full bridal affair, complete with white dress and ceremony, and the only thing missing is the groom. The trend has its own media expression – "botchi-zoku", referring to individuals who consciously choose to do things completely on their own.

    One recent weekday afternoon, Chihiro Higashikokubaru, a 23-year-old nurse, travelled 90 minutes from her home, to Tokyo on her day off in order to enjoy some solo time. Speaking quietly at the entrance of the café, Miss Higashikokubaru said: "I heard about this place via Twitter and I like the idea of coming here. I work as a nurse and it's always very busy. There are very few quiet places in Tokyo, and it's a big busy city. I just want to come and sit somewhere quietly on my own. I'm going to drink a cup of tea and maybe do some drawings. I like the idea of a quiet, calm atmosphere."

    The desire to be isolated is not a new concept in Japan, home to an estimated 3.6 million "hikikomori" – a more extreme example of social recluses（隐士）who withdraw completely from society.

A Lesson Plan from Life Planning Education: A Youth Development Program

    Purpose: To learn about body language and how to use body language.

    Materials (材料): Cards; container

    Time: 25-35 minutes

    Planning Notes:

    ·Write the words below on cards:

    angry disappointed shy afraid sad happy nervous excited bored

    ·Place the cards in the container so volunteers can draw them out one at a time.

    Steps:

    First make sure that all volunteers know what body language means (expressing feelings through body movement and facial expressions). Go over the following instructions:

    ·I'll need at least 9 volunteers to play a game similar to charades (猜词游戏).

    ·The first volunteer will draw a card with a feeling written on it and act out the feeling without using words.

    ·The rest of the group will guess what feeling is being communicated. Once someone correctly guesses the feeling, the next person in line will draw a card and act out what is written on it, again without words.

    ·The game will continue until there are no more cards or until time is up.

    At last, end the activity using the discussion points below:

    ·Can you give examples of when someone's body language communicated a different message from what he/she actually skid?

    ·Sometimes one person is offended (冒犯) by another's body language. How can you work to keep that from happening? Answers may include: be honest and direct; match your nonverbal messages to your verbal ones; be aware of (清楚) cultural attitudes toward different kinds of body language.

    Water is a necessity of life. Rain, especially, helps plants grow and stay green. But too much rain, especially in cities, can lead to flooding. That can cause waste water systems to overflow and send pollutants into rivers and other waterways. To fight the problem, several cities in the United States are starting programs like rooftop gardens.

    A team at the University of the District of Columbia in the nation's capital has created a garden on the top of one school building. The garden holds many kinds of plants to help absorb rainwater and grow food at the same time. Architect David Bell has designed five "green roofs" for the university. He says he is excited about the project because "it meant doing something more than just dealing with storm water management. It took advantage of a resource above the city and these flat roofs that aren't doing anything really became something that was about urban agriculture." Rainwater is collected in large containers and sent through a system that waters the rooftop garden. The roof is filled with green life that appeals to insects.

    In cities, "you don't have that many spaces to choose from and so rooftops are just (unused) space," says Caitlin Arlotta. She is a student in the school's Urban Agriculture program. The project is part of a research program to see which plants do well on rooftops. The researchers are looking at plants including strawberries, tomatoes and sweet potatoes. The university also has other green spaces. "We also have our own farm experiments," Arlotta said. "Within each of those growing systems, we want to be able to tell people which sorts of these crops grow the best."

    Sandy Farber Bandier helps run UDC's Master Gardener program. It seeks to improve cities and make them beautiful by training people to become Master Gardeners. She says she's been surprised by the garden's output. "My biggest surprise was that we produced 4, 250 pounds of produce the first year and was able to spread that to people in need." She also likes being able to show people who live in D. C. and others beyond the nation's capital what and how food can be grown on a rooftop. "This is the future for food. You grow it here, you prepare it in a commercial kitchen, you distribute through farmers markets, food trucks, and then you recycle."