Self-driving vehicles will rely on cameras, sensors and artificial intelligence (AI) to recognize and respond to road and traffic conditions, but sensing is the most effective for objects and movement in the neighborhood of the vehicle. Not everything important in a car's environment will be caught by the vehicle's camera. Another vehicle approaching at high speed on a collision (碰撞) track might not be visible until it's too late. This is why vehicle-to-vehicle communication is undergoing rapid development. Our research shows that cars will need to be able to chat and cooperate on the road, although the technical challenges are considerable.

    Applications for vehicle- to-vehicle communication range from vehicles driving together in a row, to safety messages about nearby emergency vehicles. Vehicles could alert each other to avoid collisions or share notices about passers-by and bicycles.

    From as far as several hundred meters away, vehicles could exchange messages with one another or receive information from roadside units (RSUs) about nearby incidents or dangerous road conditions through 4G network. A high level of AI seems required for such vehicles, not only to self-drive from A to B, but also to react intelligently to messages received. Vehicles will need to plan, reason, strategize and adapt in the light of information received in real time and to carry out cooperative behaviors. For example, a group of autonomous vehicles might avoid a route together because of potential risks, or a vehicle could decide to drop someone off earlier due to messages received, a foreseen crowding ahead.

    Further applications of vehicle- to-vehicle communication are still being researched, including how to perform cooperative behavior.

    At first glance Esther Okade seems like a normal 10-year-old. She loves dressing up, playing with Barbie dolls and going to the park or shopping. But what makes the British-Nigerian youngster stand out is the fact that she's also a university undergraduate.

    Esther, from Walsall, an industrial town in the UK's West Midlands region, is one of the country's youngest college freshmen. The talented 10-year-old enrolled at the Open University, a UK-based distance learning college, in January and is already top of the class, having recently scored 100% in a recent exam.

    "It's so interesting. It has the type of maths I love. It's real maths-theories, complex numbers, all that type of stuff," she smiles. "I want to finish the course in two years. Then I'm going to do my PhD in financial maths when I'm 13. I want to have my own bank by the time I'm 15 because I like numbers and I like people and banking is a great way to help people." she adds.

    Esther has always jumped ahead of her peers. She sat her first Math GSCE exam, a British high school qualification, at Ounsdale High School in Wolverhampton at just six, where she received a C-grade. A year later, she got the A-grade she wanted. Then last year she scored a B-grade when she sat the Math A-level exam.

    Not content with breaking barriers to attend college at just 10 years old, Esther is also writing a series of math workbooks for children called "Yummy Yummy Algebra."

    "It starts at a beginner level-that's volume one. But then there will be volume two, and volume three, and then volume four. As long as you can add or subtract, you'll be able to do it. I want to show other children they are special." she says.

    On a freezing cold day, a couple had to move into a small apartment because of their failure in business. The husband worked day and night to support the family but gave no care of his wife. So she thought, "He doesn't love me any more. He just cares about his business ... not me"．

    One day, she was about to take a shower when he stopped her at the door, "Let me take it first, okay?" "Why not me first?" she asked. "I am tired, honey, you take it later, okay?" She was entirely unhappy.

    One day, she found nothing to do and turned on his computer. A few words came into her sight. Reading them, she burst into tears. It was his diary：

    Today, I was quite sad. She asked me why I was always taking the shower first, and I said to her, "I was exhausted." She was unhappy. In her mind, I treated her not as well as usual, but what could I do? I was not as rich as before! We moved to the small apartment, and there was only one shower in the bathroom. It was so cold to take a shower in such a cold winter. But I found that if one person took the shower first, the room could get a little warmer. So every day I rushed to the bathroom first. I was thinking that, when she took the shower, the room would get warmer, even if it was only 1℃.

    Now I cannot give her a comfortable life, take her to good restaurants, or buy expensive dresses for her, but at least, I can give her 1℃ love.

    The United States estimates that about one out of every 10 people on the planet today is at least 60 years old. By 2050, it's projected to be one out of 5. This means that not only will there be more old people, but there will be relatively fewer young people to support them.

    Professor Richard Lee of the University of California at Berkeley says this aging of the world has a great effect on economics. "Population aging increases the concentration of population in the older ages and therefore it is expensive," he said.

    Aging populations consume (消耗) more and produce less. With more people living longer, it could gel expensive. But Mr. Lee says with continuing increases in worker productivity and wise planning, it can be manageable.

    Societies have different methods for caring for the elderly，but each carries a cost Generally, there are three types of support Seniors can live off the wealth they gained when they were younger. They can rely on their family to take care of them, or they can rely on the movement.

    In industrialized nations, governments created publicly-funded (公共资助的) support systems. These worked relatively well until recent years, when aging population growth in places like the United States and Western Europe began to gradually weaken the systems' finances(资金). These nations now face some tough choices. Mr. Lee says the elderly in some of these countries must either receive less money, retire later or increase taxes to make the system continuable.

    Most developing nations haven't built this type of government-funded support, but have instead relied on families to care for their elderly. These nations also generally have a much younger population, which means their situation is not as urgent as more developed nations. But Mr. Lee says that doesn't mean they can pay no attention to the issue. "Third World countries should give very careful thought to this process, to population aging and how it may affect their economies — now, before population aging even becomes a problem," he explained.

    Amsterdam, the capital and most populous city in the Netherlands, is one of the most popular travel destinations in the world, famous for its beautiful canals, top art museum, cycling culture, and Red Light District. Here are some of the key points to remember as you plan your trip to Amsterdam.

    Must-See Attractions

    Most visitors begin their Amsterdam adventure in the Old Centre, which is full of traditional architecture, shopping centers, and coffee shops. You'll also want to check out Amsterdam's Museum Quarter in the South District, which is great for shopping at the Albert Cuyp Market and having a picnic in the Vondelpark. The top museums to visit are the Rijksmusuem, the Ann Frank House, and the Van Gogh Museum. The Canal Ring is a UNESCO World Heritage Site that was originally built to attract wealthy home owners and is a popular place for celebrity spotting and nightlife today.

    Transportation

    Travelers should be aware that Amsterdam Airport Schiphol is one of the busiest airports in the world. This airport is located about 15 kilometers southwest of city center. You can catch a train from Schiphol to Amsterdam Central Station, which has many connecting routes. It's typically not a good idea to drive a car to the city center because traffic is heavy and parking is difficult to find. Cycling is incredibly popular here, and it's easy to find cheap bike rentals around town. Amsterdam has a flat terrain (地形) and is a great city to explore on foot.

    Money Saving Tips

    Unless you really want to see the tulips (郁金香) blooming, avoid booking between mid-March and mid-May. This is when hotel and flight prices rise.

    Look for accommodations in Amsterdam's South District, where rates are generally cheaper than in the city center.

    Buy train tickets at the machine instead of the counter to save a bit of money.

    Instead of hiring a tour guide, hop on a canal boat. They're inexpensive and will give you a unique point of view of the city.

    Check out our homepage to view price comparisons for flights, hotels, and rental cars before you book.

    Along the river banks of the Amazon and the Orinoco there lives a bird that swims before it can fly, flies like a fat chicken, eats green leaves, has the stomach of a cow and has claw s ( 爪) on its wings when young. They build their homes about 4.6m above the river, an important feature for the safety of the young. It is called the hoatzin.

    In appearance, the birds of both sexes look very much alike with brown on the back and cream and red on the underside. The head is small, with a large set of feathers on the top, bright red eyes, and blue skin. Its nearest relatives are the common birds, cuckoos. Its most striking feature, though, is only found in the young.

    Baby hoatzins have a claw on the leading edge of each wing and another at the end of each wing tip. Using these four claws, together with the beak (喙), they can climb about in the bushes, looking very much like primitive (远古的) birds must have done. When the young hoatzins have learned to fly, they lose their claws.

    During the drier months between December and March hoatzins fly about the forest in groups of 20 to 30 birds, but in April, when the rainy season begins, they collect together in smaller living units of two to seven birds for producing purposes.