When my brother and I were young, my mom would take us on Transportation Days.

    It goes like this: You can't take any means of transportation more than once. We would start from home, walking two blocks to the rail station. We'd take the train into the city center, then a bus, switching to the tram, then maybe a taxi. We always considered taking a horse carriage in the historic district, but we didn't like the way the horses were treated, so we never did. At the end of the day, we took the subway to our closest station, where Mom's friend was waiting to give us a ride home—our first car ride of the day.

    The good thing about Transportation Days is not only that Mom taught us how to get around. She was born to be multimodal (多方式的). She understood that depending on cars only was a failure of imagination and, above all, a failure of confidence—the product of a childhood not spent exploring subway tunnels.

    Once you learn the route map and step with certainty over the gap between the train and the platform, nothing is frightening anymore. New cities are just light-rail lines to be explored. And your personal car, if you have one, becomes just one more tool in the toolbox—and often an inadequate one, limiting both your mobility and your wallet.

    On Transportation Days, we might stop for lunch on Chestnut Street or buy a new book or toy, but the transportation was the point. First, it was exciting enough to watch the world speed by from the train window. As I got older, my mom helped me unlock the mysteries that would otherwise have paralyzed my first attempts to do it myself: How do I know where to get off? How do I know how much it costs? How do I know when I need tickets, and where to get them? What track, what line, which direction, where's the stop, and will I get wet when we go under the river?

    I'm writing this right now on an airplane, a means we didn't try on our Transportation Days and, we now know, the dirtiest and most polluting of them all. My flight routed me through Philadelphia. My multimodal mom met me for dinner in the airport. She took a train to meet me.

    On Monday, the Centers for Disease Control and Prevention predicted that 42% of Americans could be overweight by 2030. Our expanding bodies not only lead to a medical problem, but also endanger personal safety in some situations—in an airplane crash, for example, according to a recent article in The New York Times.

The New York Times' Christine Negroni reports that engineers and scientists are questioning whether airplane seats are designed to protect overweight travelers. Government standards(标准) for airplane seat strength—first set more than 60 years ago—require that the seats be made for a passenger weighing 170 pounds. Today, the average American man weighs nearly 194 pounds and the average woman 165 pounds. Negroni reports:

     “If a heavier person completely fills a seat, the seat is not likely to behave as designed during a crash,” Robert Salzar, the leading scientist at the Center for Applied Biomechanics at the University of Virginia. “The energy that is built into the aircraft seat is likely to be overpowered and the passengers will not be protected properly”.

     “Nor would the injury be limited to that passenger only,” Dr. Salzar said. “If a seat or a seat belt fails,”he said, “those people who are seated nearby could not be safe from the uncontrolled movements of the passenger.”

    Most complaints(投诉) about airplane seats focus on their lack of comfort and high ticket price, and whether overweight passengers should be made to buy two seats. But The New York Times' article brings up another reason to feel anxious about flying. Investigators(调查者) got in touch with the airplane seat and seat belt makers, but they refused to talk about the problem. Experts agreed that crash testing should be done. Both airplane seats and seat belts should be tested, they said.

    Fortunately, however, according to Nora Marshall, a senior adviser at the National Transportation Safety Board, the board's investigators have never seen an accident involving a commercial plane in which the weight of a passenger was a problem.

    In the fall of 1985, I was a bright-eyed girl heading off to Howard University, aiming at a legal career and dreaming of sitting on a Supreme Court bench somewhere. Twenty-one years later I am still a bright-eyed dreamer and one with quite a different tale to tell.

    My grandma, an amazing woman, graduated from college at the age of 65. She was the first in our family to reach that goal. But one year after I started college, she developed cancer. I made the choice to withdraw from college to care for her. It meant that school and my personal dream would have to wait.

    Then I got married with another dream: building my family with a combination of adopted and biological children. In 1999, we adopted our first son. To lay eyes on him was fantastic－and very emotional. A year later came our second adopted boy. Then followed son No,3. In 2003, I gave birth to another boy.

    You can imagine how fully occupied I became, raising four boys under the age of 8! Our home was a complete zoo — a joyous zoo. Not surprising, I never did make it back to college fulltime. But I never gave up on the dream either. I had only one choice: to find a way. That meant taking as few as one class each semester.

    The hardest part was feeling guilty about the time I spent away from the boys. They often wanted me to stay home with them. There certainly were times I wanted to quit, but I knew I should set an example for them to follow through the rest of their lives.

    In 2007, I graduated from the University of North Carolina. It took me over 21 years to get my college degree!

    I am not special, just single-minded. It always struck me that when you're looking at a big challenge from the outside, it looks huge, but when you're in the midst of it, it just seems normal Everything you want won't arrive in your life on one day. It's a process. Remember: little steps add up to big dreams.

    Technology is always trying to meet our needs and demands. 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 "recreate 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 restaurant than homes and high-end restaurants.

    A man was going to open a shop selling hats. He wanted a good sign to put over his shop. He wrote:

    JOHN BROWN HATTER

    Makes and Sells Hats for Ready Money

    The first friend gave him the advice that the word "hatter" wasn't needed. So John crossed out the hatter. Then he came to another friend for advice. This friend said that it was not polite to say "for ready money". So he crossed out "for ready money'.

    The sign now said:

    JOHN BROWN

    Makes and Sells Hats

    One day a friend was passing his shop. He saw this sign and said that when a man bought a hat, he didn't ask who made it. So John crossed out "makes".

    But when another friend saw "John Brown sells hats", he said "Of course you sell hats. No one thinks you give them away."

    So, at last the sign read:

    JOHN BROWN

    Luke has always been my closest and constant companion these past five years. In fact, he is very friendly to me especially when I take care of other furry friends in our shelter.

    There have been a lot of forest fires during the summer season. Not far from our shelter, a forest caught fire during this hot summer. Luke rushed towards the forest where flames send out a terrible heat. There's no longer any hope at the moment to wait for Luke to come back to the shelter. In fact, I was waiting for the firemen to announce me his death in the forest. Suddenly, a fireman burst into my office and informed me that my dog Luke succeeded in saving four cats which were trapped by the flames. Luke seized the kittens, one by one moving them to a safe place.

    I immediately accompanied the fireman to the forest to pick up the rescued kittens, but Luke was not there. Then we heard the sound of a dog came from the forest barking furiously. The firemen followed the tracks of the dog until they found him barking loudly by the side of an injured fireman who was lying on the ground.

    That day, I was very proud of Luke for his two heroic actions. I paid a visit to the fireman accompanied with my adorable Luke. What a memorable scene when the fireman hugged Luke tightly to his chest! “One thousand thanks, Luke, for saving my life,” the fireman said.

    This true story of love shows us that pets are kind, loving, and caring. We should love and protect them. Don't belittle them. Little animals can make enormous things for humans.