You may know the English letters A, B and C. But do you know there are people called ABC? You may like eating bananas. But did you know there is such thing as a “banana person”? How strange! Are these people from “another earth”? No. They are just Chinese people like you and me.

    ABC means American-born Chinese. An ABC is a Chinese, but was born in the United States. Sometimes, people call an ABC a “banana person”. A banana is yellow outside and white inside. So, when a person is a banana, he or she is white inside-thinking like a Westerner and yellow outside-looking like a Chinese.

    Do you know why? Usually, ABCs know little about China or the Chinese language. Some of them don't speak Chinese. Also, they are not interested in Chinese politics.

    But if ABCs cannot speak Chinese, can we still call them Chinese people? Yes, of course. They are Chinese. They are overseas (海外的) Chinese. These people may be citizens(公民) of another country like the US, Canada or Singapore. But they have Chinese blood. Their parents, grandparents or even great-grandparents were from China. They all have black eyes and black hair. But they are not Chinese citizens. They are not people of the People's Republic of China. For example, we all know the famous scientist C. N. Yang (杨振宁). He got the Nobel Prize for Physics in 1957. Chinese people love him. But he is an American citizen.

    In Western countries, bread is one of the most important foods. When they get up in the morning many people eat toast (烤面包). They spread butter and jam on their toast. People eat bread at other times of the day too. For example, at main meals, they often eat bread with soup.

    It's also very common to eat sandwiches. A sandwich is two pieces of bread with a filling inside - salad, cheese or fish. A hamburger is a kind of sandwich.

There are many different kinds of bread. Some are special to some countries. For example, the baguette (法国棍子面包) is a long, thin loaf that began in France.

    There is also white bread and whole-wheat (全麦面) bread. What's the difference? White bread is refined (精制的). It has things taken out of it to make it softer and easier to eat. The trouble is, white bread also has lots of goodness taken out. Although some people dislike the taste of whole-wheat bread, it is much healthier.

    Some kinds of bread have additives (添加剂). They are put into the bread for many reasons. Some additives are good for you - for example vitamin C. Others are there to make the bread last longer. Still others to make it taste better - but they do not necessarily make the bread healthier to eat!

    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.

72 hours in Beijing

    Traveling to China is no longer a luxury for many foreign passport holders. The Chinese government has permitted a 72-hour visa-free policy that offers access to visitors from 53 countries including the US, France and Austria. Let's start with the capital of China, Beijing Here's a pick of the best in Beijing!

    Mutianyu Great Wall

    Your trip to Beijing isn't really complete without seeing one of the "New Seven Wonders of the World", the Great Wall of China. The Mutianyu section of the Great Wall is by far the most well-preserved of all. Taking a one hour bus ride, Mutianyu would be your ideal location for a half-day of hiking away from the large crowds in the city. Also, the authorities have allowed tourists to paint graffiti on a specific section of the Great Wall since 2014. The Great Wall was designated a UNESCO World Heritage site in 1987.

    798 Art Zone

    This would be on the top of my list! Named after the 798 factory that was built in the 1950s, the art zone is home to various galleries, design studios, art exhibition spaces, fashionable shops and bars. You could easily spend half your day wandering around the complex, feeling the contrast of the present and the past.

    Summer Palace

    Located in northwestern Beijing, the Summer Palace is by far the city's most well-preserved royal park. With its huge lake and hilltop views, the palace offers you a pastoral escape into the landscape of traditional Chinese paintings. The Summer Palace was added to the UNESCO World Heritage List in 1998.

    Sichuan Provincial Restaurant

    While in Beijing, apart from trying the city's best-known Peking duck, the Sichuan provincial restaurant is one of places where you can enjoy regional delicious food. It offers one of China's eight great cuisines, Sichuan, which ranges from Mapo tofu to spicy chicken.

Preparing Cities for Robot Cars

    The possibility of self-driving robot cars has often seemed like a futurist's dream, years away from materializing in the real world. Well, the future is apparently now. The California Department of Motor Vehicles began giving permits in April for companies to test truly self-driving cars on public roads. The state also cleared the way for companies to sell or rent out self-driving cars, and for companies to operate driverless taxi services. California, it should be noted, isn't leading the way here. Companies have been testing their vehicles in cities across the country. It's hard to predict when driverless cars will be everywhere on our roads. But however long it takes, the technology has the potential to change our transportation systems and our cities, for better or for worse, depending on how the transformation is regulated.

    While much of the debate so far has been focused on the safety of driverless cars (and rightfully so), policymakers also should be talking about how self-driving vehicles can help reduce traffic jams, cut emissions (排放) and offer more convenient, affordable mobility options. The arrival of driverless vehicles is a chance to make sure that those vehicles are environmentally friendly and more shared.

    Do we want to copy—or even worsen—the traffic of today with driverless cars? Imagine a future where most adults own individual self-driving vehicles. They tolerate long, slow journeys to and from work on packed highways because they can work, entertain themselves or sleep on the ride, which encourages urban spread. They take their driverless car to an appointment and set the empty vehicle to circle the building to avoid paying for parking. Instead of walking a few blocks to pick up a child or the dry cleaning, they send the self-driving minibus. The convenience even leads fewer people to take public transport—an unwelcome side effect researchers have already found in ride-hailing (叫车) services.

    A study from the University of California at Davis suggested that replacing petrol-powered private cars worldwide with electric, self-driving and shared systems could reduce carbon emissions from transportation 80% and cut the cost of transportation infrastructure (基础设施) and operations 40% by 2050. Fewer emissions and cheaper travel sound pretty appealing. The first commercially available driverless cars will almost certainly be fielded by ride-hailing services, considering the cost of self-driving technology as well as liability and maintenance issues (责任与维护问题). But driverless car ownership could increase as the prices drop and more people become comfortable with the technology.

    Policymakers should start thinking now about how to make sure the appearance of driverless vehicles doesn't extend the worst aspects of the car-controlled transportation system we have today. The coming technological advancement presents a chance for cities and states to develop transportation systems designed to move more people, and more affordably. The car of the future is coming. We just have to plan for it.

    A new officer with the Huntington Park Police patrols (巡逻) local parks 24 hours a day seven days a week. He doesn't need rest, coffee breaks, a salary or medical insurance, and that is because it is a Robocop.

    The main function of the Robocop is to scan and film the surroundings. Besides cameras with night vision that report 360 degrees, it also has a distress button which is located here, so if somebody is to need assistance or they want to contact the communication center, they can do it by way of that distress button. There are people that are monitoring on the other end.

    This newest police employee is self-charging. It's easy to program it and make changes to the software if necessary. Its maintenance (维护) costs are roughly 75 thousand dollars a year. It travels the entire park. It is a programmed path, but the police are able to change the path and adapt it.

    The Robocop can record the license plates (车牌) of passing cars and check them against an online database of stolen cars. It can also help locate a lost iPhone because it is able to determine a smartphone's MAC address. The police can see from the robot if something wrong happens and then come and figure it out.

    The Robocop can't replace its human handlers. The whole goal is to give police more time to do things machines can't do. The police have been having some concerns about safety of the parks and want an extra set of eyes that will help patrol a 24/7.Robocop's creators believe this model known as K5 is best used for providing security at public places like hospitals, parking lots, parks and airports. So far, it seems to be working out just fine.