The Healthy Habits Survey shows that only about one third of American seniors have correct habits . Here are some findings and expert advice.

Top 5 Must See Places in Beijing

    Beijing is an old capital city with a lot of tourists attractions. What is the most representative place in Beijing? The answers are various. Here are the Top 5 Must See Places in Beijing.

1）. Forbidden City

    The Forbidden City is the ideal place for you to begin your exploration of Beijing. Make sure to wear comfortable shoes as you have to walk a lot! A multilingual guide recorder is recommended, as it can tell you the stories behind the palace.

Opening Hour: 8:30-17:00

Entrance Fee: RMB 60

2）. Tian'anmen Square

    Lying in the heart of Beijing City, it is the place for massive parades and gathering. It boasts of the largest square of such kind in the world. At sunrise and sunset the raising and lowering ceremony of the Chinese National Flag is well worth seeing.

Ticket fees: Free

Opening Time: Whole Day

3）. Great Wall

    Most of the sections of the Great Wall in Beijing are well-preserved, and the most famous section is Badaling. For the Great Wall hiking, get ready for strong footwear. For hot weather, please also prepare sunblock, sunglasses and water.

Badaling Great Wall:

Ticket Fees: RMB40 (Nov. 01 to Mar. 31); RMB 45 (Apr. 01 to Oct. 31)

Open Hours: 6:40 to 18:30

4）. Summer Palace

    Regarded as the largest imperial garden in China, the Summer Palace is in fact a park-styled royal retreat. With masterly design and artistic architecture integrating the highlight of Chinese garden arts, it has earned a title of "Royal Garden Museum".

Open Time: 6:30-20:30

Ticket Fee: RMB 40 (low season) / RMB 50 (peak season during the holidays)

5）. Temple of Heaven

    The Temple of Heaven worked as sacrificial compound buildings for the Ming and Qing emperors. What's the intriguing by-production of the temple is that if you enter the Temple of Heaven in the early morning, you can find many people doing all types of Kungfu, Taiji, dancing and other morning exercises.

Open Time: 6:00-21:00

Ticket Fee: RMB 35

    Scientists say we are all born with a knack for mathematics. Every time we scan the cafeteria for a table that will fit all of our friends, we're exercising the ancient estimation center in our brain.

    Stanislas Dehaene was the first researcher to show that this part of the brain exists. In 1989, he met Mr. N who had suffered a serious brain injury. Mr. N couldn't recognize the number 5, or add 2 and 2. But he still knew that there are “about 50 minutes” in an hour. Dehaene drew an important conclusion from his case: there must be two separate mathematical areas in our brains. One area is responsible for the math we learn in school, and the other judges approximate amounts.

    So what does the brain's estimation center do for us? Harvard University researcher Elizabeth Spelke has spent a lot of time posing math problems to preschoolers. When he asks 5-year-olds to solve a problem like 21+30, they can't do it. But he has also asked them questions such as, “Sarah has 21 candles and gets 30 more. John has 34 candles. Who has more candles?” It turns out preschoolers are great at solving questions like that. Before they've learned how to do math with numerals and symbols, their brains' approximation centers are already hard at work.

    After we learn symbolic math, do we still have any use for our inborn math sense? Justin Halberda at Johns Hopkins University gave us an answer in his study. He challenged a group of 14-year-olds with an approximation test: The kids stared at a computer screen and saw groups of yellow and blue dots flash by, too quickly to count. Then they had to say whether there had been more blue dots or yellow dots. The researchers found that most were able to answer correctly when there were 25 yellow dots and 10 blue ones. When the groups were closer in size, 11 yellow dots and 10 blue ones, fewer kids answered correctly.

    The big surprise in this study came when the researcher compared the kids' approximation test scores to their scores on standardized math tests. He found that kids who did better on the flashing dot test had better standardized test scores, and vice versa (反之亦然). It seems that, far from being irrelevant, your math sense might predict your ability at formal math.

    In 2016, three viruses made news, and they present difficult problems for health officials in the New Year. One virus threatens babies in many parts of the world. Another has reappeared in an African nation. And a third is one of the deadliest viruses of modern times. The three viruses are Zika, polio and HIV. However, in 2016 scientists and researchers from all over the world worked to make progress against those viruses and to develop better ways to control them.

    The spread of the Zika virus caused public health officials in many nations to put in place strong measures to control its spread.

    Brazil, which hosted the 2016 Summer Olympic Games, was hit hard by the virus. Health officials warned pregnant women against traveling to the sporting event. Zika is usually a mild illness. It is so mild that most people who are infected do not know they have it. However, in the past two years in the Western Hemisphere, Zika has been linked to babies being born with extremely small heads. This condition is called microcephaly. The international medical community found that this link to birth defects makes Zika a very dangerous virus.

    Zika first appeared in Uganda more than 60 years ago. It is spread by mosquitos and by sex. The virus recently appeared in Brazil. Then cases appeared in other countries to the North. Cases were reported in the United States in the southern state of Florida. Health officials in Texas are also concerned the virus might be spreading there.

    Doctors can only advise women to be careful. They advise women not to travel to areas where the virus is spreading, to avoid mosquito bites or to delay pregnancy. Currently there is no vaccine against Zika. However, one could be available by 2018.

    Plastic waste has polluted the Arctic. Two new studies have spied bags, fishing rope and tinier bits of rubbish in the Barents Sea. This sea sits north of Norway, Sweden, Finland and Russia. It mixes with the Arctic Ocean, which is even farther north.

    Plastic waste in the Arctic could harm wildlife and may hint that large volumes of human rubbish are collecting there, says Melanie Bergmann. She is one of the scientists who spotted the waste. She studies Earth's oceans at the Alfred Wegener Institute in Bremerhaven, Germany. She first started counting bits of plastics in the Barents Sea because she kept spotting signs of the stuff there in images taken with deep-sea cameras.

    Bergmann and her colleagues counted pieces of plastic from an icebreaker, a boat designed to break through large blocks of ice in very cold waters. They also tracked plastic pieces they saw during helicopter rides over Arctic waters. The team found 31 pieces of plastic. “That doesn't seem like much, but it shows us that we've really got a problem, one that extends even to this remote area, far from civilization,” Bergmann says. She and her colleagues described their findings October 21 in Polar Biology.

    Another team has also been counting plastics in the area. Those scientists took water from the Barents Sea and counted the number of smaller bits of plastics, called microplastics.

    Plastic in the ocean is dangerous to animals. Some may get caught in rope or bags. And wildlife may swallow bags and other plastic bits. That makes them feel full. But some may eventually starve because they are not getting the nutrients they need to live. Sometimes plastics also may break down in an animal's body and release poisonous chemicals. If another animal later eats the one that swallowed plastic, it too can end up with poisonous chemicals in its body. This, in turn, can travel up the food web, endangering predators (肉食动物) — even people.

    Solar energy systems/power plants do not produce air pollution, water pollution, or greenhouse gases. Using solar energy can have a positive, indirect effect on the environment, when solar energy replaces or reduces the use of other energy sources that have larger effects on the environment.

    However, some poisonous materials and chemicals are used to make the photovoltaic (光电池的) cells that convert sunlight into electricity. Some solar thermal (保热的) systems use potentially hazardous liquids to transfer heat. Leaks of these materials could be harmful to the environment. U. S. environmental laws regulate the use and settlement of these types of materials.

    As with any type of power plant, large solar power plants can affect the environment near their locations. The placement of the power plant may have long-term effects on the habitats of native plants and animals. Some solar power plant-s may require water for cleaning solar collectors and concentrators or for cooling turbine generators. Using large volumes of ground water or surface water in some dry locations may affect the ecosystems that depend on these water resources. In addition, the beam of concentrated sunlight a solar power tower creates can kill birds and insects that fly into the beam.

    The amount of solar energy that the earth receives each day is many times greater than the total amount of all energy that people consume each day. However, on the surface of the earth, solar energy is a variable and irregular energy source. The amount of sunlight and the intensity of sunlight varies by time of day and location. Weather and climate conditions affect the availability of sunlight daily and on a seasonal basis. The type and size of a solar energy collection and conversion system determines how much of the available solar energy we can convert into useful energy.