What would it be like to walk on Mars? If you could build the highest building in the world，what would it look like? Do you dream of being the next J. K. Rowling? This summer, you can experience all of these things, and more. All you need is an Internet connection and your imagination.

    A recent study by the Kaiser Family Foundation found that kids spend an average of 1 hour and 29 minutes online each day. Many kids like to use that time to chat with friends, play games or check e­mails. But the next time you get on the Web, try exploring the world instead. “With the Internet，you can go back 11,000 years in time，or go 11,000 kilometers across the planet.” said Russell, Web search expert of Google. “The whole scope of history and the world is open to you.”

    There is a wealth of information to be found online. For example, if your family is going on vacation somewhere, do a quick online search on the area before you even get in the car. “What's the background of the place; what's the history？” says Russell. “I like to tell my kids, ‘Whenever you have a question, whenever you have a doubt, search it out.'”

    Ready to launch a virtual journey of your own? Here are a few starting points to get you thinking and to help you on your way. You can invite your parents along for the ride, too. Always ask for permission before downloading programs and software onto your computer. And check with a parent or an adult before visiting any new Web site.

    Navigate the world in 3­D with Google Earth. Begin in outer space and zoom (快速移动) into the streets of any city, from Hong Kong to San Francisco. Or visit ancient monuments, watch the changing rainforests over time, and dive underwater to explore tropical reef.

    With the Moon in Google Earth tool, you can walk in Neil Armstrong's famous footsteps. Take a guided tour of the moon's surface with Armstrong's fellow shuttle mate astronaut Buzz Aldrin.

    When you're exploring that part of the solar system, hop on over to the Red Planet with Google Mars. There, you can move very quickly around the surface and see images from the Mars Rovers.

    NANJING, Nov. 4 (Xinhua) — Xi Jinping and Ma Ying-jeou will shake hands in their historic meeting scheduled in Singapore on Saturday, head of the Taiwan Affairs Office of the State Council said on Wednesday.

    The two-part meeting includes one session open to the media and another behind closed doors, said Zhang Zhijun, who is also head of the Taiwan Work Office of the Communist Party of China (CPC) Central Committee, when interviewed at the Zijinshan Summit for Entrepreneurs across the Taiwan Strait.

    According to Zhang, Xi and Ma, as "leaders of the two sides" of the Taiwan Strait, will exchange views during the closed-door meeting.

    After the meeting, press conferences will be held by both sides. Later, the two leaders are expected to attend a dinner, said Zhang.

    Zhang said the meeting will lift cross-Strait communication to a new high.

The landmark meeting is a breakthrough in face-to-face exchange and communication between the leaders across the Taiwan Strait after the relationship became strained following the events of 1949.

    Zhang said the meeting will improve mutual trust and allow for an exchange of opinions on handling the cross-Strait ties.

    In addition, the meeting will help strengthen the 1992 Consensus(共识), which was reached in talks between the two sides in 1992 and recognizes the one-China principle, and safeguards the peaceful development of cross-Strait ties, according to Zhang.

    Zhang added that the scheduled meeting will also benefit regional peace and stability.

    Also at Wednesday's summit, Chiang Pin-kung, former chairman of the Taiwan-based Straits Exchange Foundation, hailed the upcoming meeting between the two leaders as a milestone for cross-Strait ties.

    Chiang told the media that he believed the meeting will give a boost to the peaceful development of cross-Strait ties.

    This could be Micah Fitz, first spring without football practices. The 14-year-old has been playing since he was 3, but because he's home-schooled, he can't try out for the local team at Patriot High School in Prince William County, Virginia.

    “I can't play this half of the year and my friends are going to be playing five or six times a week,” he said. “They're going to be getting better and stronger playing with kids that are good.”

Micah and his family—along with many other home-schooling families across Virginia—are hoping the Virginia General Assemble will approve a bill this year that would allow kids like him to try out for sports on public school athletic teams. The bill, called the “Tebow bill”, is named after football player Tim Tebow, who was home-schooled but was allowed to play on a high school team before going to the University of Florida, where he led his team to two national championships.

    Many major statewide education organizations said the bill wouldn't be fair to public school students. Ken Tilley, the executive director of the Virginia High School League, said the bill would violate two of the league's most long-standing standards for qualification: enrollment (注册入学) and academic standing.

    Home-school advocates argue that they are required by the law to document academic progress. But many opponents say students always have the option of attending public high school. That might be what Sydney Bowman, a 12-year-old from Luchetts, will do to keep wrestling, although she would prefer to continue to be taught at home. In her case, girls' wrestling teams are rare enough that there aren't many options other than public school.

    But Micah' mom, Terri Fits, a former public school teacher, said that although they support the local schools and love to cheer on the teams, they like the flexibility of home-schooling.

    At your next meeting, wait for a pause in conversation and try to measure how long it lasts.

    Among English speakers, chances are that it will be a second or two at most. But while this pattern may be universal, our awareness of silence differs dramatically across cultures.

    What one culture considers a confusing or awkward pause may be seen by others as a valuable moment of reflection and sign of respect for what the last speaker has said. Research in Dutch and also in English found that when a silence in conversation stretches to four seconds, people start to feel uneasy. In contrast, a separate study of business meetings found that Japanese people are happy with silences of 8.2 seconds — nearly twice as long as in Americans' meetings.

    In Japan, it is recognized that the best communication is when you don't speak at all. It's already a failure to understand each other by speaking because you're repairing that failure by using words.

    In the US, it may originate from the history of colonial (殖民地) America as a crossroads of many different races. When you have a complex of difference, it's hard to establish common understanding unless you talk and there's understandably a kind of anxiety unless people are verbally engaged to establish a common life. This applies also to some extent to London.

    In contrast, when there's more homogeneity, perhaps it's easier for some kinds of silence to appear. For example, among your closest friends and family it's easier to sit in silence than with people you're less well acquainted with.

    As a result of pollution, Lake Erie, on the borders of the USA and Canada, is now without any living things.

    Pollution in water is not simply a matter of “poisons” killing large numbers of fish overnight, Very often the effects of pollution are not noticed for many months or years because the first organisms（生物体）to be affected are either plants or plankton. But these organisms are the food of fish and birds and other creatures. When this food disappears, the fish and birds die too. In this way a whole food chain can be wiped out, and it's not until dead fish and water birds are seen at the river's edge or on the seashore that people realize what is happening.

    Where do the substances which pollute the water come from? There are two main sources of sewage（污水）and industrial waste . As more detergent（洗涤剂）is used in the home, so more of it is finally put into our rivers, lakes and seas . Detergents harm water birds, dissolving the natural substances which keep their feathers water - proof. Sewage itself, if not properly treated, makes the water dirty and prevents all forms of life in rivers and the sea from receiving the oxygen they need. Industrial waste is even more harmful as there are many highly poisonous things in it, such as copper and lead（铅）.

    So, if we want to stop this pollution, the answer is simple: sewage and industrial waste must be made clear before flowing into the water. It may already be too late to save some rivers and lakes, but others can still be saved if the correct action is taken at once.

    Since English biologist Charles Darwin published On the Origin of Species in 1859, scientists have vastly improved their knowledge of natural history. However, a lot of information is still of the speculation, and scientists can still only make educated guesses at certain things.

    One subject that they guess about is why some 400 million years ago, animals in the sea developed limbs (肢) that allowed them to move onto and live on land.

    Recently, an idea that occurred to the US paleontologist (古生物学家) Alfred Romer a century ago became a hot topic once again.

    Romer thought that tidal (潮汐的) pools might have led to fish gaining limbs. Sea animals would have been forced into these pools by strong tides. Then, they would have been made either to adapt to their new environment close to land or die. The fittest among them grew to accomplish the transition (过渡) from sea to land.

    Romer called these earliest four-footed animals “tetrapods”. Science has always thought that this was a credible theory, but only recently has there been strong enough evidence to support it.

    Hannah Byrne is an oceanographer (海洋学家) at Uppsala University in Sweden. She announced at the 2018 Ocean Sciences Meeting in Oregon, US, that by using computer software, her team had managed to link Homer's theory to places where fossil deposits (沉积物) of the earliest tetrapods were found.

    According to the magazine Science, in 2014, Steven Balbus, a scientist at the University of Oxford in the UK, calculated that 400 million years ago, when the move from land to sea was achieved, tides were stronger than they are today. This is because the planet was 10 percent closer to the moon than it is now.

    The creatures stranded in the pools would have been under the pressure of “survival of the fittest”, explained Mattias Green, an ocean scientist at the UK's University of Bangor. As he told Science, “After a few days in these pools, you become food or you run out of food... the fish that had large limbs had an advantage because they could flip (翻转) themselves back in the water.”

    As is often the case, however, there are others who find the theory less convincing. Cambridge University's paleontologist Jennifer Clark, speaking to Nature magazine, seemed unconvinced. “It's only one of many ideas for the origin of land-based tetrapods, any or all of which may have been a part of the answer,” she said.