More and more Americans are showing an interest in healthy and locally-produced food. As the interest increases, raising chickens has been gaining popularity in some American cities.

 “Look, we get three eggs this time.”

    Collecting eggs is a daily pleasure for the Hurst family. Naomi Hurst says her family started to raise chickens in back of their home in Maryland a month ago.

   “We have wanted to try having backyard chickens for a couple years now. And really just didn't have the time to build my own coop（鸡笼；鸡舍） and  look out where to buy chickens. And then we met Rent a Coop,” said Naomi Hurst. Rent a Coop is a chicken rental business. Tyler Phillips launched the company with a partner 18 months ago. It comes with a mobile coop on wheels, two egg-laying hens, feed, bedding, water bowl, feed bowl, and our 24-hour chicken hotline. You can call with any questions. The price is 185 dollars for four weeks. After the four weeks passed, individuals can extend the rental agreement, return everything or purchase the animals and supplies.

Tyler Phillips designs and makes the coops. He says he wants to do as little damage as possible to the environment.

 “We always try to have as many recycled materials as possible. And I want the coops to be safe for kids. I want the chickens to be comfortable and they have access to the grass while being inside the coop. I want it to be easily movable, light weight,” he said.

Some cities require people have large pieces of land, if they want to raise farm animals. Others require an agreement with neighbors, limit the number of chickens, or, even ban the birds.

  Tyler Phillips expects that would change as interest in small poultry (家禽) coops grows. 

“I see cities around the D. C. area changing laws almost monthly and different cities will change the law to being prochicken(赞成养鸡). That is happening all around the United States,” he said,

He believes that there will be chicken rental businesses in most American cities within five years.

    Visitor Oyster cards are electronic smart cards that come fully charged with credit. Whether you're making a one-off trip to London or you're a regular visitor, using an Oyster travel smart card is the easiest way to travel around the city's public transport network. Simply touch the card on the yellow card reader at the doors when you start and end your journey.

Advantages of a Visitor Oyster Card

    A Visitor Oyster card is one of the cheapest ways to pay for single journeys on the bus, Tube, DLR, tram, London Overground and most National Rail services in London:

● Save time—your card is ready to use as soon as you arrive in London.

● It's more than 50% cheaper than buying a paper travel card or single tickets with cash.

● There is a daily price cap—once you have reached this limit, you won't pay any more.

● Enjoy special offers and promotions at leading London restaurants, shops and entertainment venues—plus discounts on the Emirates Air Line cable car and Thames Clippers river buses.

Buy a Visitor Oyster card

    Buy a Visitor Oyster card before you visit London and get it delivered to your home address. A card costs￡3 (non-refundable) plus postage. Order online and arrive with your Oyster in hand! You can also buy a Visitor Oyster card from Gatwick Express ticket offices at Gatwick Airport Station and on board Eurostar trains travelling to London.

Add Credit to Your Visitor Oyster Card

    You can choose how much credit to add to your card. If you are visiting London for two days, you can start with ￡20 credit. If you run out of credit, add credit at the following locations:

● Touch screen ticket machines in Tube, DLR, London Overground and some National Rail stations .

● Around 4,000 Oyster Ticket Stops found in newsagents and small shops across London.

● TFL Visitor and Travel Information Centers .

● Tube and London Overground station ticket offices .

● Emirates Air Line terminals .

    Mexico sites on an island plateau (高原) surrounded by volcanic peaks, which makes air quality a constant concern for people who live there.

    In April, the country took a decisive step toward improving air quality by enacting a temporary ban on private and Federal vehicles in the city. The rule forbids people from driving in the city one day each week and one Saturday each month. Electric vehicles, government service vehicles, public transport options and school buses are not included in the ban.

    Mexico City isn't the first urban center to be involved in car-free living. But the ban is more than an awareness-raiser. It was enacted with the direct aim of solving air pollution. In March, the city sank into a deep brown haze of smog when the pollution levels passed the 200 mark. The city ordered some 1.1m of the area's 4.7m cars off the streets and also offered free bus and subway rides.

    Mexico City's temporary vehicle ban raises questions about the best ways to improve urban air quality. India, whose citizens breathe some of the world's dirtiest air, has tried a variety of solutions. Earlier this year, the Indian government started a 4% sales tax on new-car purchases.

    Beijing also has experience with cleaning the air. The city introduced alternate-day rules in advance of the 2008 Olympic Games, which produced good results. And then there is the London congestion (拥挤) charge, introduced in 2003. The charge has had a measurable effect on air quality.

For now, Mexico City — named by the United Nations as the most polluted city on the planet in 1992 — can look forward to the start of the region's rainy season, when daily showers will help lo clean the air.

    The new social robots, including Jibo, Cozmo, Kuri and Meccano M.A.X., bear some similarities to assistants like Apple's Siri, but these robots come with something more. They are designed to win us over not with their smarts but with their personality. They are sold as companions that do more than talk to us. Time magazine cheered for the robots that "could fundamentally reshape how we interact with machines." But is reshaping how we interact with machines a good thing, especially for children?

    Some researchers in favor of the robots don't see a problem with this. People have relationships with many kinds of things. Some say robots are just another thing with which we can have relationships. To support their argument, roboticists sometimes point to how children deal with toy dolls. Children animate (赋予…生命) dolls and turn them into imaginary friends. Jibo, in a sense, will be one more imaginary friend, and arguably a more intelligent and fun one.

    Getting attached to dolls and sociable machines is different, though. Today's robots tell children that they have emotions, friendships, even dreams to share. In reality, the whole goal of the robots is emotional trickery. For instance, Cozmo the robot needs to be fed, repaired and played with. Boris Sofman, the chief executive of Anki, the company behind Cozmo, says that the idea is to create "a deeper and deeper emotional connection ... And if you neglect him, you feel the pain of that." What is the point of this, exactly? What does it mean to feel the pain of neglecting something that feels no pain at being neglected, or to feel anger at being neglected by something that doesn't even know it is neglecting you?

    This should not be our only concern. It is troubling that these robots try to understand how children feel. Robots, however, have no emotions to share, and they cannot put themselves in our place. No matter what robotic creatures "say", they don't understand our emotional lives. They present themselves as empathy machines, but they are missing the essential equipment. They have not been born, they don't know pain, or death, or fear. Robot thinking may be thinking, but robot feeling is never feeling, and robot love is never love.

    What is also troubling is that children take robots' behavior to indicate feelings. When the robots interact with them, children take this as evidence that the robots like them, and when robots don't work when needed, children also take it personally. Their relationships with the robots affect their self-esteem (自尊). In one study, an 8-year-old boy concluded that the robot stopped talking to him because the robot liked his brothers better.

    For so long, we dreamed of artificial intelligence offering us not only simple help but conversation and care. Now that our dream is becoming real, it is time to deal with the emotional downside of living with robots that "feel".