阅读下列短文，从每题所给的四个选项(A、B、C和D)中选出最佳选项。

    If cars had wings，they could fly and that just might happen，beginning in 2011.The company Terrafugia，based in Woburn，Massachusetts，says it plans to deliver its car­plane，the Transition，to customers by the end of 2011.

    “It's the next ‘wow' vehicle，” said Terrafugia vice president Richard Gersh.“Anybody can buy a Ferrari，but as we say，Ferraris don't fly.”

    The car­plane has wings that unfold for flying－a process the company says takes one minute－and fold back up for driving. A runway is still required to take off and land.

    The Transition is being marketed more as a plane that drives than a car that flies，although it is both. The company has been working with FAA to meet aircraft regulations，and with the National Highway Traffic Safety Administration to meet vehicle safety regulations.

    The company is aiming to sell the Transition to private pilots as a more convenient and cheaper way to fly. They say it saves you the trouble from trying to find another mode of transportation to get to and from airports：You drive the car to the airport and then you're good to go. When you land，you fold up the wings and hit the road. There are no expensive parking fees because you don't have to store it at an airport－you park it in the garage at home.

    The car­plane is designed to fly primarily under 10,000 feet. It has a maximum takeoff weight of 1,430 pounds，including fuel and passengers. Terrafugia says the Transition reduces the potential for an accident by allowing pilots to drive under the bad weather instead of flying into marginal(临界的) conditions.

    The Transition's price tag：$194,000.But there may be additional charges for options like a radio，a transponder or a GPS. Another option is a full­plane parachute.

    “If you get into a very awful situation，it is the necessary safety option，” Gersh said.

    So far，the company has more than 70 orders with deposits. “We're working very closely with them，but there are still some remaining steps，” Brown said.

    It is good to get in touch with your inner child from time to time，and obviously some people are willing to pay big money for the chance to do so in a proper environment．A Brooklyn-based adult preschool is charging customers between $333 and $999 for the chance to act like a kid again．

At Preschool Mastermind in New York adults get to participate in show—and—tell，arts—and—crafts such as finger paint，games like musical chairs and even take naps．The month-long course also has class picture day where the adults are expected to have a field trip and a parent day.30-year-old Michelle Joni Lapidos，the brain behind the adult preschool，studied childhood education and has always wanted to be a preschool teacher．She's always on the lookout for new ways to get people in touch with the freedom of childhood．A friend encouraged her to start the mastermind course instead．

    According to Candice，her blogger friend，Preschool Mastermind gives adults a chance to relearn and master the things that they failed to understand as children．“I realized all the significances of what we learn in preschool，”said founder Michelle Joni，“People come here and get in touch with their inner child．It's magical．We are bringing ourselves back to another place，another time with ourselves when we are more believing in ourselves，more confident and ready to take on the world.”

    “One person's here because they want to learn not to be so serious．”Michelle said．“Another's here to learn to be more confident.” She explained that most of the classes were planned．However，Joni added that while the planned activities were fun，it was often the spontaneous(自发的)moments that attracted students．“It's the things you don't plan for，the sharing between friends and learning from each other.''

    There's a new frontier in 3D printing that's beginning to come into focus: food. Recent development has made possible machines that print, cook, and serve foods on a mass scale. And the industry isn't stopping there.

     Food production

    With a 3D printer, a cook can print complicated chocolate sculptures and beautiful pieces for decoration on a wedding cake. Not everybody can do that — it takes years of experience, but a printer makes it easy. A restaurant in Spain uses a Foodini to "re-create forms and pieces" of food that are "exactly the same," freeing cooks to complete other tasks. In another restaurant, all of the dishes and desserts it serves are 3D-printed, rather than farm to table.

    Sustainability(可持续性)

    The global population is expected to grow to 9.6 billion by 2050, and some analysts estimate that food production will need to be raised by 50 percent to maintain current levels. Sustainability is becoming a necessity. 3D food printing could probably contribute to the solution. Some experts believe printers could use hydrocolloids (水解胶体) from plentiful renewables like algae(藻类) and grass to replace the familiar ingredients(烹饪原料). 3D printing can reduce fuel use and emissions. Grocery stores of the future might stock "food" that lasts years on end, freeing up shelf space and reducing transportation and storage requirements.

    Nutrition

    Future 3D food printers could make processed food healthier. Hod Lipson, a professor at Columbia University, said, "Food printing could allow consumers to print food with customized nutritional content, like vitamins. So instead of eating a piece of yesterday's bread from the supermarket, you'd eat something baked just for you on demand."

    Challenges

    Despite recent advancements in 3D food printing, the industry has many challenges to overcome. Currently, most ingredients must be changed to a paste(糊状物) before a printer can use them, and the printing process is quite time-consuming, because ingredients interact with each other in very complex ways. On top of that, most of the 3D food printers now are restricted to dry ingredients, because meat and milk products may easily go bad. Some experts are skeptical about 3D food printers, believing they are better suited for fast food restaurants than homes and high-end restaurants.

    How are you and your family going to celebrate Earth Day? It's a great day to get outside and ride a bike, but there are other ways you could spend the day. Here are four books. You can learn more about the earth and the animals that make the world a special place to live in.

    The Busy Beaver, by Nicholas Oldland

    Beaver is very, very busy, and he doesn't always think carefully. As a result, he makes a mess of the forest and ends up in hospital. Finally, he realizes how careless he's been and decides to make things right when he returns to the forest.

    Lessons from Mother Earth, by Elaine Mcleod

    Five-year-old Tess is visiting her grandmother and, for the first time, she visits the garden. Along the way, Tess's grandmother tells her the rules of the garden, "You must always take good care of our garden. Never throw rubbish around. There is plenty for everyone to share if we don't destroy the soil." The story is beautifully told as a caring conversation between a child and her grandmother.

    Luz Sees the Light, by Claudia Davila

    When Luz's community(社区) experiences a series of black-outs(停电), she quickly comes to understand the need to save energy and find other ways of doing things. With the help of her friends and neighbors, she creates a community garden and park that everyone can use. The book attracts many young readers.

    The Lorax, by Dr Seuss

    A young boy learns of the role of the Lorax as protector(保护者) of the trees, and how his home became polluted. The book contains memorable forestry conservation (森林保护).

    Sheffield

    Lincoln College of English

    Classes for foreign students at all levels.

    3 months, 6 months, 9 months and one year course.

    Open all year.

    Small class (at most 12 students).

    Library, language laboratory and listening center.

    Accommodation (住宿) with selected families.

    25 minutes from London.

    Course fees for English for one year are ￡ 1,380 with reduction for shorter periods of study.

    Many people have long dreamed of being able to fly around as simply as riding a bicycle. Yet the safety and strength of a flying bike was always a big problem. Over the past 10 years, developments in technology have moved the dream of personal flying vehicles closer to reality. Now, two groups of inventors say such vehicles may be available soon.

    The British company Malloy Aeronautics has developed a prototype (原型) of its flying bicycle. Grant Stapleton, marketing sales director of Malloy Aeronautics, says the Hoverbike is able to get in and out of small spaces very quickly." It can be moved across continents very quickly because it can be folded and packed," he adds.

    Mr. Stapleton says safety was the company's main concern. He says the designers solved the safety issue by using overlapping rotors to power the vehicle.

    The company is testing a full-size prototype of the Hoverbike, which will most likely be used first by the police and emergency rescue teams.

    In New Zealand, Martin Aircraft Company is also testing a full-size prototype of its personal flying device, called the Jetpack. It can fly for more than 30 minutes, up to 1, 000 meters high and reach a speed of 74 kilometers per hour.

    Peter Coker is the CEO of Martin Aircraft Company. He said the Jetpack "is built around safety from the start". In his words, "Reliability is the most important element of it. We have safety built into the actual structure itself, very similar to a Formula One racing car.

    The Jetpack uses a gasoline-powered engine that produces two powerful jet streams. Mr. Coker says it also has a parachute that would be used, if there should be an emergency. "It starts to work at very low altitude and actually saves both the aircraft and the pilot," he adds. Mr. Coker says the Jetpack will be ready for sale soon.