I look back sometimes at the person I was before I rediscovered my old professor. I want to talk to that person. I want to tell him what to look out for, what mistakes to avoid. I want to tell him to be more open, to ignore the temptation of advertised values, to pay attention when your loved ones are speaking, as if it were the last time you might hear them.

    Mostly I want to tell that person to get on an airplane and visit a gentle old man in West Newton, Massachusetts, sooner rather than later, before that old man gets sick and loses his ability to dance.

    I know I cannot do this. None of us can undo what we've done, or relive a life already recorded. But if Professor Morrie Schwartz taught me anything at all, it was this: there is no such thing as “too late” in life. He was changing until the day he said good-bye.

    Not long after Morrie's death, I reached my brother in Spain. We had a long talk. I told him I respected his distance, and that all I wanted was to be in touch—in the present, not just the past—to hold him in my life as much as he could let me.

    “You're my only brother,” I said. “I don't want to lose you. I love you.”

    I had never said such a thing to him before. A few days later, I received a message on my fax machine. It was typed in the sprawling, poorly punctuated, all-cap-letters fashion that always characterized my brother's words.

    “HI I'VE JOINED THE NINETIES!” it began. He wrote a few little stories, what he'd been doing that week, a couple of jokes. At the end, he signed off this way:

I HAVE HEARTBURN AND DIAHREA(腹泻) AT THE MOMENT—LIFE'S A BITCH. CHAT LATER?

[signed] SORE TUSH.

I laughed until there were tears in my eyes.

    This book was largely Morrie's idea. He called it our “final thesis.” Like the best of work projects, it brought us closer together, and Morrie was delighted when several publishers expressed interest, even though he died before meeting any of them. The advance money helped pay Morrie's enormous medical bills, and for that we were both grateful.

    The title, by the way, we came up with one day in Morrie's office. He liked naming things. He had several ideas. But when I said, “How about Tuesdays with Morrie?” he smiled in an almost blushing way, and I knew that was it.

    After Morrie died, I went through boxes of old college material. And I discovered a final paper I had written for one of his classes. It was twenty years old now. On the front page were my penciled comments scribbled to Morrie, and beneath them were his comments scribbled back.

    Mine began, “Dear Coach . . .”

    His began, “Dear Player . . .”

    For some reason, each time I read that, I miss him more.

    Have you ever really had a teacher? One who saw you as a raw but precious thing, a jewel that, with wisdom, could be polished to a proud shine? If you are lucky enough to find your way to such teachers, you will always find your way back. Sometimes it is only in your head. Sometimes it is right alongside their beds.

    The last class of my old professor's life took place once a week, in his home, by a window in his study where he could watch a small hibiscus(木槿) plant shed its pink flowers. The class met on Tuesdays. No books were required. The subject was the meaning of life. It was taught from experience.

    The teaching goes on.

    A great woman once said, “Women must try to do things as men have tried. When they fail, their failure must be a challenge to others. “These are the words of US pilot Amelia Earhart（1897- 1937）, a pioneer in aviation（航空领域）, who was the first woman to fly across the Atlantic Ocean

    Her story ended in mystery when she disappeared without a trace（踪迹）during a flight over the Pacific Ocean. Theories about what happened to Earhart were proposed, but nothing was ever confirmed—until now. A study published in March conducted by Richard Jantz from the University of Tennessee, US, determined that bones found in 1940 on a remote Pacific island belonged to Earhart. Following the discovery, the world's memories of the legendary female pilot were brought back to life.

    Earhart was born in 1897. When she was young, she was very interested in stories about women who were successful in male-dominated（男性为主的）professions, such as engineering and law. But in 1920, Earhart's life changed after her first experience of being a plane passenger. As soon as the plane left the ground, Earhart knew that she loved flying, so she found herself a teacher and started to learn how to fly for herself. To pay for the lessons and buy a plane of her own, she took all sorts of jobs.

    In 1932, Earhart flew solo（独自地）across the Atlantic, becoming the first woman ever to do so. She also designed a flying suit for women and went on to design other clothes for women who led active lives. When she was nearly 40, Earhart was ready for a final challenge—to be the first woman to fly around the world. Her first attempt was unsuccessful but she tried again in 1937 with her navigator（领航员）Fred Noonan. But one month later, they disappeared in bad weather in mid-flight.

    Even though it's still not clear how she ended up on the island, we're one step closer to finding the answer. And no matter what, Earhart will be forever remembered as a brave pioneer, both as a pilot and as a woman.

    Green is an important color in nature. It is the color of grass and the leaves on trees. It is also the color of most growing plants.

    Sometimes, the word "green" means young, fresh and growing. For example, a greenhorn is someone who has no experience. In the 15th century, a greenhorn was a young cow or an ox whose horns(角)had not yet developed. A century later, a greenhorn was a soldier who had no experience in war. By the 18th century, a greenhorn had the meaning it has today—a person who is new in a job.

    Someone who is good at growing plants is said to have a green thumb(大拇指). The expression comes from the early 20th century. A person with a green thumb can make plants grow quickly and well.

    Green is also the color used to describe the powerful feeling , jealousy(嫉妒). The green-eyed monster （怪物）is not a dangerous animal from outer space. It is an expression used about 400 years ago by the British writer William Shakespeare in his play "Othello". It describes the unpleasant feeling when someone has something he wants. For example, a young man may suffer from the green-eyed monster if you get a pay rise and he does not.

    In most places in the world, a green light means to move ahead. In everyday speech, a green light means agree to continue with a project.

    For many students who desire to move around but not far freely, one of the most common vehicles is the bicycle. For such a seemingly simple invention, its story is not that simple.

    Most historians trace its origin back to 1817, when a German nobleman named Karl von Drais invented a wooden, two­wheeled machine that riders moved forward with their feet. His invention became popular in both England and France, where it eventually became known as the velocipede. Unfortunately, it was eventually banned as a danger to pedestrians and was rarely seen after the early 1820s.

    Things were quiet for several decades until the bicycle development took off in the 1860s. An important milestone happened in Paris in 1863 when pedals were added to the front axle (轴). This occurred in Pierre Michaux's workshop, but it's unclear whether he or his employee, Pierre Lallement, should be given credit for the innovation Lallement moved to the United States, where he obtained a patent for "improvements in velocipedes" in 1866. These new machines proved to be popular, and the name "bicycle" had come into use by 1869. However, many people referred to them as "bone shakers", which described their clunky ride due to a heavy wooden frame and steel wheels.

    In the 1870s, "high wheelers" or "penny­farthings" became popular. However, with a large front wheel and a much smaller rear wheel, they could be dangerous, if riders had to stop suddenly, as they would "take a header" when their momentum (动量) carried them over the front wheel onto their heads. Eventually, English inventor John Kemp Starley designed a "safety bicycle" with two same small wheels, a chain drive, and a set of gears. With tires added in and brake systems bettered in the following decades, bicycle production had skyrocketed to over one million bicycles by 1899.

    Mass production of bicycles increased their popularity greatly, since they became affordable for the average person. Over the course of the 20th century, manufacturers continued to improve the features and design of bicycles as new technologies appeared.

    Brian Hamilton's life changed in a prison when he was accompanying his friend, Reverend Robert J. Harris, who often went to local prisons to do his work. During the visit, Hamilton started talking to one of the prisoners and asked what he was going to do when he got out.

    "He said he was going to get a job," Hamilton recalls(回忆). "I thought to myself, wow, that's going to be difficult with a criminal background."

    The conversation made Hamilton consider how prisoners could benefit from entrepreneurship, something he thought about for years. Finally in 2008, 16 years after that initial conversation, Hamilton created Inmates to Entrepreneurs, a nonprofit organization that helps people with criminal backgrounds start their own small businesses. "Harris and I taught our first course at a prison called 'How to Start Your Own Business When You Get Out'," he recalls.

    At the time, Hamilton was building his own company, Sageworks. As Sageworks grew, so did Hamilton's time spent teaching at prisons throughout North Carolina.

    Eventually, Hamilton decided it was time to change his focus to his true passion. In May 2018, he sold his stake(股份) in Sageworks, focusing his commitment on Inmates to Entrepreneurs.

    "Now, anyone is able to access the curriculum, either to become an instructor to go into prisons to teach it or to access it for themselves as a prisoner or part of the general population," Hamilton explains. In addition, he visits middle schools and presents the curriculum to at-risk students as a preventative measure against crime.

    The free curriculum is funded by the recently established Brian Hamilton Foundation, which offers assistance to military members as they adjust to civilian life and provides loans to small businesses. "We're giving prisoners something they can do independent of a system that isn't working for them. If you can let people know that other people care about them, it makes a difference."

    NASA's (美国宇航局的) newly announced space tourism program is possibly the biggest mistake in the agency's history.

    Beginning as early as 2020, NASA will offer visits to the International Space Station for $35,000 per night, not including transportation, to pretty much anyone who can pass a physical.

    The reason this is a mistake, and a big one, is that NASA has worked for generations to create an image of astronauts as extraordinarily skilled, highly trained, courageous heroes. For example, NASA invites grade schools to participate in creating experiments that are carried on the space station. The astronauts talk to kids from space, sending a message that if you study, work hard and learn math and science, you may reach these heights, too.

    According to one report, Las Vegas-based Bigelow Aerospace is making plans to haul four tourists at a time to the space station on SpaceX rockets. U.S. taxpayers forked over a hundred billion dollars to build the International Space Station. It would be nice to try to preserve the image of it as an inspirational achievement, instead of turning it into a flying Howard Johnson's.

    NASA's press release about the space tourism program tries to cast it as a partnership with the private sector to "provide expanded opportunities" at the space station to "manufacture, market and promote commercial products and services." But it also states that one goal is "quantifying NASA's long-term demand for activities in low-Earth orbit."

    The space station has been costing U.S. taxpayers between $1.5 billion and $3 billion each year. If it's perceived as a private Disneyland for the top tax bracket, public support for the entire space program could be at risk.

    But worse, we will have degraded what once inspired us. Sometimes a nation needs stars in its eyes.