It is interesting to see that the force of only 6 or 7 people pushing in the same direction can cause up to 1,000 pounds of force-enough to break brick walls. During a deadly stampede(逃奔), people can even die standing up. People die when pressure is put to their bodies in a front to back direction, causing them not to be able to breathe.

    If you are in a crowd, the first and most important thing is to make yourself familiar with your surroundings and find different exits. No matter where you are, make sure you always know how to get out.

    Make yourself aware of the type of the ground you are standing on, and know that in a crowd of moving people wet ground can cause you to fall.

    When in danger, a few seconds can make a difference, giving you the possibility of making use of your escaping route. Always stay closer to the escape route. If you find yourself in the middle of a moving crowd, do not fight against the pressure, do not stand still or sit down, because you can easily get trampled（踩踏）. Instead, move in the same direction of the crowd; make use of any space that may open up to move sideways to the crowd movement where the flow is weaker.

    Keep your hands up by your chest, like a boxer-it gives you movement and protects your chest. If you fall, get up quickly. If you can't get up because you are injured, get someone to pull you up. If you have kids, lift them up.

    If you fall and cannot get up, keep moving in the same direction of the crowd, or if that is not possible, then cover your head with your arms; do not lie on your stomach or back.

    Explore the possibility of using the iPad App Store in the classroom.

    App Name: Bridge Constructor/Cost: $1.99

    Bridge Constructor lets players build increasingly challenging bridges over deep valleys, canals and rivers. Stress tests reveal whether the bridge kids build can withstand continual use from cars, trucks, and more recently, super-heavy tank trucks. Players can choose from among a range of bridge-building materials such as wood, steel, cables and concrete pillars (混凝土柱). Each bridge also has a budget, and there are numerous ways to successfully complete each challenge.

App Name: Pyramid Adventure 3-D/Cost: $13.99

    The interface allows users to fly around the plateau where the pyramids and the Sphinx are located at Giza near Cairo. Interactive, three-dimensional maps let students wander around the labyrinthine tombs and passageways. Uses can examine wall paintings in detail, or view royal statues and objects with a 360-degree feature. To help explain the world of ancient Egyptians, the app offers an accompanying interactive book, specially written by world-famous Egyptologist Zahi Hawass.

    App Name: Grammar Up/Cost: $4.99

    Grammar Up is a multiple-choice quiz system for English grammar. Kids and adults can learn most quickly when playing learning games with real-time error feedback, which Grammar Up provides. The app also offers students practice tests so they can see how much they've learned. A summary is presented at the end of each test, showing the time spent, a score, and the questions answered correctly and incorrectly. The results are also e-mailable.

    Being seen in a fancy sports car or enjoying a beach holiday in a five-star hotel were once signs of having “made it”.

    But a new study suggested that having people think of you as constantly busy and overworked is now a far better way to show social status.

    According to Harvard University in the US, people are increasingly leaning toward the phenomenon of “humblebragging (谦虚自夸)”. This is when people make a seemingly modest statement that actually draws attention to something they want to brag (吹嘘) about.

    Phrases such as “I have no life” and “I desperately need a holiday” are now used to imply social standing, while ordering food and shopping online is the perfect way to prove to neighbors that you are simply too busy and important to go to the supermarket.

    “Movies, magazines, and popular TV shows often highlight (强调) the abundance (富足) of money and leisure time among the wealthy,” said Neeru Paharia, an assistant professor at Harvard University.

    “In recent years, featuring wealthy people relaxing by the pool or on a yacht (游艇), playing tennis or skiing and hunting are being replaced with advertisements featuring busy individuals who work long hours and have very limited leisure time,” he said. “Displaying (how busy you are at work) and a lack of leisure time operates as a visible signal of status in the eyes of others.”

    The researchers pointed out that the Wall Street Journal's 2016 advert campaign featured celebrities (名人) complaining about their busy lives, with the slogan (标语). “People who don't have time, make time to read the Wall Street Journal.”

    The report, which was published in the Journal of Consumer Research, also found that brands that marketed themselves as timesaving were becoming increasingly high-status, because of the people who used them.

    According to the authors, this trend of humblebragging is due to people's shit of focus-they now value “the preciousness und scarcity (稀缺) of individuals" more than “the preciousness and scarcity of goods”.

    “Busy individuals possess desirable characteristics, leading them to be viewed as scarce and in demand,” the authors concluded.

    Plan on traveling around the USA this summer? If you need help in arranging the trip, or want ideas about where to go and what to do, there are a number of outstanding websites that can make your American dream come true.

    If you don't have a college degree, you're at greater risk of developing memory problems or even Alzheimer's (老年痴呆). Education plays a key role in lifelong memory performance and risk for mental disorder, and it's well documented that those with a college degree possess a cognitive（认知的） advantage over their less educated counterparts in middle and old age.

    Now, a large national study from Brandeis University published in the American Journal of Geriatric Psychiatry shows that those with less schooling can significantly make up for poorer education by frequently engaging in mental exercises such as word games, puzzles, reading, and lectures.

    “The lifelong benefits of higher education for memory in later life are quite impressive, but we do not clearly understand how and why these effects last so long,” said lead author Margie Lachman, a psychologist. She suggested that higher education may encourage lifelong interest in cognitive efforts, while those with less education may not engage as frequently in mental exercises that help keep the memory agile (敏捷地).

    But education early in adulthood does not appear to be the only route to maintain your memory. The study found that intellectual activities undertaken regularly made a difference. “Among individuals with low education, those who are engaged in reading, writing, attending lectures, doing word games or puzzles once a week or more had memory scores similar to people with more education,” said Lachman.

The study, called Midlife in the United States, assessed 3,343 men and women between the ages of 32 and 84 with a mean age of 56 years. Almost 40 percent of the participants had at least a 4-year college degree. The researchers evaluated how the participants performed in two cognitive areas, verbal memory and executive function — brain processes involved in planning, abstract thinking and cognitive flexibility. Participants were given a battery of tests, including tests of verbal fluency, word recall, and backward counting.

    As expected, those with higher education said they engaged in cognitive activities more often and also did better on the memory tests, but some with lower education also did well, explained Lachman.

    “The findings are promising because they suggest there may be ways to level the playing field for those with lower educational achievement, and protect those at greatest risk for memory declines,” said Lachman. “Although we can not rule out the possibility that those who have better memories are the ones who take on more activities, the evidence is consistent with cognitive plasticity (可塑性), and suggests some degree of personal control over cognitive functioning in adulthood by adopting an intellectually active lifestyle.”

    The Adler Planetarium(天文馆) is part of the lake front's "Museum Campus", which along with the Shedd Aquarium(水族馆) and Field Museum, attracts a huge number of visitors every year. The Adler Planetarium is included with the purchase of a Go Chicago Card.

    Address: 1300 South Lake Shore Drive

    Phone: 312-922-STAR(7827)

    Getting to the Adler Planetarium by Public Transportation:

    Either the south-bound CTA bus line #146(Marine-Michigan), or Red Line CTA train south to Roosevelt, then take a Museum Campus trolley (电车) or take the CTA bus #12.

    Driving from Downtown of Chicago:

    Lake Shore Drive (US 41) south to 18th Street. Turn left onto Museum Campus Drive and follow it around Soldier Field. Look for signs that will point you to the visitor parking garage. The Adler Planetarium is just northeast of the parking garage.

Parking at the Adler Planetarium:

    There are several lots(停车场) on the Museum Campus, but most tend to fill up quickly and your best bet is in the main parking garage. Parking for all lots is $ 15 per day.

    Adler Planetarium Hours:

    Daily: 9：30 a. m. -- 4: 30 p. m. The Adler Planetarium is open every day except     Thanksgiving Day and Christmas. Extended Hours: From Memorial Day to Labor Day, the Adler Planetarium is open from 9: 30 a.m.--6: 00 p. m. daily.

    Adler Planetarium Tickets:

    General Admission(exhibits only): Adults, $ 7; Seniors (aged 65+), $ 6；Children(ages 4--11), $5.