Do you drink water that's been left sitting out overnight or even for another day? Have you noticed it tastes different?

    Tap water that has been left to sit out slowly begins to acquire(获得) off taste. Many people think that this is because of microorganisms. But that's not what makes old water taste not fresh. For that we can thank carbon dioxide. After about 12 hours, tap water starts to go flat as carbon dioxide in the air starts to mix with the water in the glass, lowering its pH and giving it an off taste. But it's most likely safe to drink.

    However, back to those microorganisms. If you use a dirty glass day after day, there is more of a chance of bacteria making themselves known; a risk that increases if you share the glass with another mouth as well. But assuming(假设) you use a fresh glass every few days, you probably won't have a problem unless the glass has been touched by dirty fingers, and especially if those dirty fingers went unwashed after using the bathroom.

    As for plastic water bottles that have been left out in the sun or in the car, step away from the bottle, warns Dr. Kellogg Schwab, director of the Johns Hopkins University Water Institute. "A chemical called biphenyl-A, or BPA, along with other things used to make plastic can leach(过滤) into your water if the bottle heats up or sits in the sun," he explains. BPA, as you probably know, has been linked to everything from heart disease to cancer. Schwab also adds that plastic used for commercial bottled water isn't meant to be washed or refilled, so use only one time and recycle. Or don't buy them at all; use refillable water bottles instead.

B

Find Your Adventure at the Space and Aviation(航空) Center

    If you're looking for a unique adventure, the Space and Aviation Center (SAC) is the place to be. The Center offers programs designed to challenge and inspire with hands-on tasks and lots of fun.

    More than 750,000 have graduated from SAC, with many seeking employment in engineering, aviation, education, medicine and a wide variety of other professions. They come to camp, wanting to know what it is like to be an astronaut or a pilot, and they leave with real-world applications for what they're studying in the classroom.

    For the trainees, the programs also offer a great way to earn merit badges(荣誉徽章). At Space Camp, trainees can earn their Space Exploration badge as they build and fire model rockets, learn about space tasks and try simulated(模拟) flying to space with the crew from all over the world. The Aviation Challenge program gives trainees the chance to earn their Aviation badge. They learn the principles of flight and test their operating skills in the cockpit(驾驶舱) of a variety of flight simulators. Trainees also get a good start on their Wilderness Survival badge as they learn about water- and land-survival through designed tasks and their search and rescue of ＂downed＂ pilot.

    With all the programs, teamwork is key as trainees learn the importance of leadership and being part of a bigger task.

    All this fun is available for ages 9 to 18. Families can enjoy the experience together, too, with Family Camp programs for families with children as young as 7.

    Stay an hour or stay a week — there is something here for everyone!

    For more details, please visit us online at www.oursac.com.

    In 1812, the year Charles Dickens was born, there were 66 novels published in Britain. People had been writing novels for a century—most experts date the first novel to Robinson Crusoe in 1719—but nobody wanted to do it professionally. The steam-powered printing press was still in its early stages; the literacy（识字） rate in England was under 50%. Many works of fiction appeared without the names of the authors, often with something like “By a lady.”Novels, for the most part, were looked upon as silly, immoral, or just plain bad.

    In 1870, when Dickens died, the world mourned him as its first professional writer and publisher, famous and beloved, who had led an explosion in both the publication of novels and their readership and whose characters — from Oliver Twist to Tiny Tim— were held up as moral touchstones. Today Dickens' greatness is unchallenged. Removing him from the pantheon（名人堂） of English literature would make about as much sense as the Louvre selling off the Mona Lisa.

    How did Dickens get to the top? For all the feelings readers attach to stories, literature is a numbers game, and the test of time is extremely difficult to pass. Some 60,000 novels were published during the Victorian age, from 1837 to1901; today a casual reader might be able to name a half-dozen of them. It's partly true that Dickens' style of writing attracted audiences from all walks of life. It's partly that his writings rode a wave of social, political and scientific progress. But it's also that he rewrote the culture of literature and put himself at the center. No one will ever know what mix of talent, ambition, energy and luck made Dickens such a singular writer. But as the 200th anniversary of his birth approaches, it is possible — and important for our own culture—to understand how he made himself a lasting one.

    You probably know who Marie Curie was, but you may not have heard of Rachel Carson. Of the outstanding ladies listed below, who do you think was the most important woman of the past 100 years?

    Jane Addams(1860-1935)

    Anyone who has ever been helped by a social worker has Jane Addams to thank. Addans helped the poor and worked for peace. She encouraged a sense of community(社区)by creating shelters and promoting education and services for people in need . In 1931, Addams became the first American woman to win the Nobel Peace Prize.

    Rachel Carson(1907-1964)

    If it weren't for Rachel Carson, the environmental movement might not exist today. Her popular 1962 book Silent Spring raised awareness of the dangers of pollution and the harmful effects of chemicals on humans and on the world's lakes and oceans.

    Sandra Day O'Connor(1930-present)

    When Sandra Day O'Connor finished third in her class at Stanford Law School, in 1952, she could not find work at a law firm because she was a woman. She became an Arizona state senator(参议员) and ,in 1981, the first woman to join the U.S. Supreme Court. O'Connor gave the deciding vote in many important cases during her 24 years on the top court.

    Rosa Parks(1913-2005)

    On December 1, 1955, in Montgomery, Alabama, Rasa Parks would not give up her seat on a bus to a passenger. Her simple act landed Parks in prison. But it also set off the Montgomery bus boycott. It lasted for more than a year, and kicked off the civil-rights movement. "The only tired I was, was tired of giving in," said Parks.

    Millions of Americans are living in areas at high-risk of river flooding, many of whom are completely unaware of the danger.

    While the risk of coastal flooding from extreme storms and rising seas rightly attracts plenty of attention, Americans are being urged to look inland for a similar threat receiving far less recognition: river flooding. New research conducted by the University of Bristol has shown that as many as 41 million Americans are highly at risk from river floods – more than three times the number previously estimated – with real estate (住宅区) in areas such as Louisiana, Florida, Arizona and West Virginia found to be especially at threat.

    For the first time, it has been possible to produce super quality flood risk maps that cover the whole United States, while previous Federal Emergency Management Agency (FEMA) flood maps cover no more than 60 per cent of the country. The fine details provided by these new maps also makes it possible to predict the powerful effects of flooding on many smaller streams than before, thus raising concerns about the increasing number of people potentially threatened.

    "We were all surprised by how many Americans we find are exposed to flooding from rivers," says Oliver Wing, from the University of Bristol's School of Geographical Sciences. "It's particularly worrisome considering that most of these people aren't even aware of the risk they face."

    Additionally, there is the possibility that this lack of awareness means construction in high-risk river flooding areas will continue to rise, despite the threats. Estimates (估量) suggest that projected population growth, continued urbanization trends (城市化趋势), and the unpredictable threats caused by climate change will leave over 60 million Americans vulnerable (易受攻击的) to a 100-year flood by the middle of the century. 'All of this highlights the urgent need for large areas of floodplain and flood risk management planning,' adds Wing.

    When to go: The Magic Kingdom, which was opened in 1971, was the first theme park at Walt Disney World. All Disney World theme parks are opened 365 days a year, although opening and closing time for each park changes from day to day. If you plan to make a trip to the Magic Kingdom without kids, try to visit on a school day to avoid the largest crowds. If you need to visit during a school vacation, try at least to avoid the week between Christmas and New Year's Day and the fourth of July.

    If you are not staying at a Disney World hotel, avoid visiting the Magic Kingdom on its Extra Magic Hours days, as Disney's hotel guests get into the park early on those days, and visitors who arrive at the Magic Kingdom's normal opening time have to wait for a long time.

    Before you go：Buy your Walt Disney World tickets online at Disney World's website. For advice on picking the right ticket, see our guide to Disney World tickets.

    You will also need to call in advance to make lunch or dinner reservations. Disney accepts reservations(预订)up to 180 days in advance, but you need to contact 1-407-WDW-DINE.

    When you get there: Plan to arrive at the Magic Kingdom's front gate before the park opens in the morning. Keep in mind that to reach the Magic Kingdom, you must park at Disney World's Transportation and Ticket Centre parking lot, ride a tram (有轨电车)to the TTC, then take a ferry boat across the Seven Seas Lagoon to the Magic Kingdom. It makes a fantastic approach, but takes extra time. Give yourself an extra hour in the summer and half an hour during the school year.