In the mid-1950s, I was a somewhat bored early-adolescent male student who believed that ________________________ One day, this approach threw me into embarrassment

    In Mrs. Totten's eighth-grade math class at Central Avenue School in Anderson, Indiana, we were learning to add and subtract decimals (小数).

    Our teacher typically assigned daily homework, which would be recited in class the following day. On most days, our grades were based on our oral answer to homework questions.

    Mrs. Totten usually walked up and down the rows of desks requesting answers from student after student in the order the questions had appeared on our homework sheets. She would start either at the front or the back of the classroom and work toward the other end.

    Since I was seated near the middle of about 35 students, it was easy to figure out which questions I might have to answer. This particular time, I had completed my usual two or three problems according to my calculations.

    What I failed to expect was that several students were absent, which threw off my estimate. As Mrs. Totten made her way from the beginning of the class，I desperately tried to determine which math problem I would get. I tried to work it out before she got to me, but I had brain freeze and couldn't function.

When Mrs. Totten reached my desk，she asked what answer I'd got for problem No. 14. “I…I didn't get anything,” I answered，and my face felt warm.

    “Correct,” she said.

    It turned out that the correct answer was zero.

What did I learn that day? First, always do all your homework. Second, in real life it isn't always what you say but how you say it that matters. Third，I would never make it as a mathematician.

    If I could choose one school day that taught me the most, it would be that one.

    Golden Gate Bridge

    Located in San Francisco,the Golden Gate Bridge started in the year 1933 to connect the San Francisco Peninsula with Marin County.It was finally thrown open to public traffic in 1937.It cost $25.7 million in the construction.Till the year 1957,the Golden Gate Bridge,at a length of 2,737 meters,was the longest suspension bridge in the world.

    Brooklyn Bridge

    The Brooklyn Bridge is located in Brooklyn.It is one of the oldest suspension bridges in the United States, having been opened in the year 1883.The length of the bridge is 1,843 meters.The bridge has been featured in several Hollywood movies.

    George Washington Bridge

    Also known as the Hudson River Bridge and the Columbus Bridge,the George Washington Bridge which connects Fort Lee to Manhattan came into use in 1931 after a construction period of almost 4 years.It is a two level suspension bridge that cost about $52 million to build.

    Mackinac Bridge

    This is the third biggest suspension bridge in the world at a length of 8,038 meters.The architect of this bridge was Dr.David B. Steinman who directed the construction of the bridge which started in the year 1054 and opened to the public in 1958.People using this bridge are charged a certain amount of money.

    Navajo Bridge

    Located in Arizona,this bridge crosses the Colorado River and is almost 250 meters long.The construction of this bridge started in the year 1927,ending two years later,costing $390,000.In the 1990s a second bridge was built which was opened to the public in 1994.The first bridge is now used only by pedestrians.

    In the near future, we may be using our eyes to operate our smart-phones and tablets, even when it comes to playing popular games like Fruit Ninja.

    The Gaze Group has been developing eye-controlled computer technology for nearly 20years. But those devices have been firstly designed to help those with disabilities, and are very expensive.

    “After a while, we figured out that probably the best way is to go for a mass-market way,”says Gaze's Sune Alstrup Johansen. “Where everybody would have this available.”

    Johansen and some of his colleagues have formed a new company, the Eye Tribe, which is hoping to develop the technology on a mass commercial level.

    The technology works when combined with the computing device toward the user's face. After making sure of the user's eye movements, the technology is then able to easily find where a person's eyes are moving, and then allow the eyes to control a cursor (光标)

    “Our software can then determine the location of the eyes and know where you're looking on the screen to make sure what you're looking at, ”reads an explanation on the Eye Tribe site.

    There has been a gradual change toward hands-free technology in recent years, particularly in the gaming world. Recently Xbox released the Kinect device, which lets users control their Xbox and play certain games using only their hands, legs and voices. But still, most of these devices have been more of a gimmick than a practical way to use one's hands to control a mobile device. Johansen said a replaceable filter (滤光器) would be a cheap, convenient way for most consumers.

    And even as companies like The Eye Tribe work to create such a product for the average user, making the eye-controlled technology more accessible and less expensive will have similar benefits for physically disabled users.

    For more articles on modem science, please CLICK here.

    Venus, the Wildest Adventure in 3016!

    A trip to the moon, to Mars? You are out. Venus (金星) is your choice! Our spaceship carries you there at the speed of light!

    Amazing Venus Facts

    Temperature range: ALWAYS about 450 degrees Celsius. Great for barbecues!

    Seasons: No seasons. Always visit during best season!

    Gravity strength: 0.91 of Earth's gravity. Makes you lighter and more alive than ever!

    Water: NONE. All boiled away.

    Day length: 1 day=243 Earth days. Longest days in solar system» so fun never ends!

    Rate of turning: 0.002 km/second. Turns in opposite direction of the earth, so able to see sun rise in the west and set in the east.

    Year length: 1 year=224.7 Earth days or 0.62 of an Earth year.

    Rate of revolution: 35.03 km/second.

    Atmosphere:

    Very thick.

    96% carbon dioxide; 3% nitrogen, and 0.1% water vapor.

    Can't support life: Suffocating carbon dioxide, thick clouds of sulfuric acid, and gases create greenhouse effect so very hot and no water.

    The popular wisdom for years has been that drinking in moderation (适度)—that's one “standard” drink a day for women and two for men-is linked to a lower risk of cardiovascular (心血管的) disease. But recent studies are casting some doubt on that long-held learning. Science now says it depends on your age and drinking habits.

    A 2017 study of nearly 2 million British with no cardiovascular risk found that there was still a modest benefit in moderate drinking, especially for women over 55 who drank five drinks a week. Why that age? Alcohol can influence the substance in the blood in positive ways, experts say, and that's about the age when heart problems begin to occur.

    Also, a 2018 study found that drinking more than 100 grams of alcohol per week—equal to roughly seven standard drinks in the United States or five to six glasses of wine in the UK—increases your risk of death from all causes and in turn lowers your life expectancy. Links were found with different forms of cardiovascular disease, with people who drank more than 100 grams per week having a higher risk of stroke, heart failure.

    Another 2018 study found that consistently drinking a moderate amount of alcohol, within recommended guidelines, had a protective effect on the heart over time. Unstable drinking habits were associated with a higher risk of heart disease, which the authors reflected might indicate broader lifestyle changes, such as poor health or stress. Former drinkers were also at greater risk.

    Overall, however, the latest thinking is that any heart benefit may be outweighed by other health risks, such as high blood pressure, certain cancers and liver damage.

Women who drink are at a higher risk for breast cancer; alcohol contributes about 6% of the overall risk, possibly because it raises certain dangerous hormones in the blood. Drinking can also increase the chance you might develop liver, mouth and oral cancers. One potential reason: Alcohol weakens our immune systems, making us more likely to inflame (发炎)—a driving force behind cancer.

    The huge T­rex (霸王龙) bends over a large triceratops (三角龙) lying on his side below. With its mouth open wide, the T­rex looks ready to kill the triceratops with a final bite to the triceratops's neck. The display will be found at the National Museum of Natural History.

    The museum has sought a huge T­rex skeleton (骨架) for many years. Before, it used a model of one. But museum director Kirk Johnson says that was never good enough. "It's been kind of deeply embarrassing to be the national museum and NOT have a T­rex," he said. The T­rex display is now the centerpiece of the museum's newest show, which will be available to the public on July 15.

    That T­rex, named Sue, was found in South Dakota. Officials at the museum built a special area for the skeleton. It includes a gift store of all things related to Sue. Sue even has her own Twitter account and a media presentation of her life story.

    In modern times, movies like "Jurassic Park (侏罗纪公园)" have helped grow dinosaur interest for a new generation of young fans. But such movies describe the T­rexes as mostly huge, stupid and dangerous animals, which are true threat in the fighting: quick, intelligent and aggressive hunters in groups.