Elizabeth Freeman was born about 1742 to African American parents who were slaves. At the age of six months she was acquired, along with her sister, by John Ashley, a wealthy Massachusetts slaveholders. She became known as “Mumbet” or “Mum Bett.”

    For nearly 30 years Mumbet served the Ashley family. One day, Ashley's wife tried to strike Mumbet's sister with a spade. Mumbet protected her sister and took the blow instead. Furious, she left the house and refused to come back. When the Ashleys tried to make her return, Mumbet consulted a lawyer, Theodore Sedgewick. With his help, Mumbet sued(起诉) for her freedom.

While serving the Ashleys, Mumbet had listened to many discussions of the new Massachusetts constitution. If the constitution said that all people were free and equal, then she thought it should apply to her. Eventually, Mumbet won her freedom—- the first slave in Massachusetts to do so under the new constitution.

    Strangely enough, after the trial, the Ashleys asked Mumbet to come back and work for them as a paid employee. She declined and instead went to work for Segdewick. Mumbet died in 1829, but her legacy lived on in her many descendants(后裔). One of her great-grandchildren was W.E.B. Du Bois, one of the founder of the NAACP, and an important writer and spokesperson for African American civil rights.

    Mumbet's tombstone still stands in the Massachusetts cemetery where she was buried. It reads, in part: “She was born a slave and remained a slave and remained a slave for nearly thirty years. She could neither read nor write, yet in her own sphere she had no superior or equal.”

    It was my first day back home since starting college. A lot had changed in the last year. Not with my hometown but with me. I had left as a 17-year-old boy and had now returned as an 18-year-old man. In the city, I was living on my own, had a part-time job and was studying. Even the government recognized I was an adult: I had a driver's license. So here I was, on my summer vacation, walking down the main street with my father, desperate for him to acknowledge how mature I was. When his recognition failed to appear, I took matters into my own hands. “Dad,” I said casually, “I'm thirsty. Let's go for a beer.” It was the first time I'd ever mentioned beer in front of my father, let alone ask him to drink one with me.

    He turned to me with a curious expression on his face. “A beer? Well, 1 guess you're old enough now. Let's go to Sailors' Bar. It's where my cousin Tom, your uncle, used to drink. You remember him, right?”

    I had only some vague recollection of my uncle. He was the black sheep of the family. We didn't talk about him much. What ever happened to Uncle Tom, Dad? I haven't seen him in years,” I said as we continued towards the bar.

     “Neither have I, unfortunately. He was a good kid once. But things changed,” my father said mournfully. As a boy, he explained, there had been no better-behaved boy than Tom. But after leaving school, he moved to the city and fell in with bad company. He started going out every night, drinking in nightclubs and playing cards. Soon he lost everything and had to beg his mum to pay his debts. She agreed on condition that he returned home.

    My dad took a deep breath and continued his tale. "Things settled down for a while. He married a lovely woman, gave up his bad habits. But it didn't last. He was soon back to his old ways. He couldn't resist. He was at Sailors, Bar almost every night. His poor mother died of grief and shame. His wife followed her soon after.

     “What ruined him was alcohol He told me once, when a man begins drinking, he never knows where it'll end. ‘So', Tom warned me. ‘be cautious about your first drink!'

     “He went from bad to worse. Last year Tom sent me a letter saying he had been found guilty of stealing, and sent to prison for ten years.”

    Dad finished talking just as we reached the front door of Sailors' Bar. “Anyway, here we are. Let's go in,” he said. But understood. I put my arm around my father and said, “I'm not thirsty anymore, Dad. Let's go home.”

    The American Academy of Pediatrics (AAP) (儿科学) just released its updated guidelines for children's media use.

    The recommendations reflect what all parents know: children need less screen time, which indicates that they desperately need more free time to develop their imagination, a sense of wonder and discover their passion and purpose.

    Our children are over-stimulated, over-scheduled and under pressure to perform academically and beyond school. This weakens their ability to build creative thinking skills essential to self-discovery. Creativity occurs when kids have time for curiosity and exploration. With children spending up to eight hours a day on media devices and additional hours engaging in scheduled activities, opportunities for growth disappear.

    What we are not so sure about is how to get our kids to want the free, screenless time which we know will benefit them. It may sound counter-intuitive (违背直觉的) but today's kids need coaching to experience and discover the benefits of free time.

What came to parents easily a few decades ago has become a challenge for our generation. It's not that yesterday's parents knew more about child development; they simply had fewer choices. Boredom and relaxation were an inescapable part of daily life. Today, they mean, "I'm a bad parent and not doing enough to get my kid ahead."

    Recently, I had an eye-opening revelation while watching my 11-year-old daughter play in a softball game. I have six children and have attended dozens of such game. I know the drill—or thought I did. Families settled in for the day with lawn chairs, cold drinks and cousins. These brothers and sisters would gradually chat with each other. Games of catch and hide-and-seek began, and friendships were formed then. At crucial moments, the newfound friends turned their attention to the field to cheer on their teams.

    But that wasn't happening. Though there were at least 15 children by the sidelines (球场边线), I didn't hear any of them. They sat in silence using their individual tablets (平板电脑). Even with the score tied in the final inning (垒球比赛的一局), not a single child watched the game or spoke to each other. The situation was strange and revealing: Kids have more planned activities and passive entertainment at their fingertips than ever before, but less free time to dream, imagine and focus on what they truly love.

I understand that making time for "nothing" is difficult in a world where we are constantly worried our kids will fall behind if they aren't good at academics. But I refuse to sit back and watch this loss of childhood. We are taking back childhood. Imagination needs time and space to blossom.

If your kids are like mine, asking them to imagine will at the beginning be difficult. That's because they haven't developed the skills and muscle memory to make it second nature. I hope the AAP guidelines prompt all of us to set needed screen time limits for our children. Personally, I am practicing strategies to "develop imagination" in my children. Imagination, like a sport, requires practice, training, motivational speeches, rewards and extreme patience.

    His Excellency

    Kim Jong Un

    Chairman of the State Affairs Commission of the Democratic People's Republic of Korea

Dear Mr. Chairman,

    We greatly appreciate your time, patience, and effort with respect to our recent negotiations and discussions relative to a summit (峰会) long sought by both parties, which was scheduled to take place on June 12 in Singapore.

    We were informed that the meeting was requested by North Korea, but that to us is totally irrelevant (不重要的). I was very much looking forward to being there with you.

    Sadly, based on the unacceptable and unfriendly statement, I feel it is not proper, at this time, to have this long-planned meeting.

    Therefore, please let this letter to serve to represent that the Singapore summit, for the good of both parties, but to the detriment of the world, will not take place.

    You talk about your nuclear capabilities (能力), but ours are so massive and powerful that I pray to God they will never have to be used.

    I felt a wonderful dialogue was building up between you and me, and ultimately, it is only that dialogue that matters. Some day, I look very much forward to meeting you.

    In the meantime, I want to thank you for the release of the hostages (人质) who are now home with their families. That was a beautiful gesture and was very much appreciated.

    If you change your mind having to do with this most important summit, please do not hesitate to call me or write. The world, and North Korea in particular, has lost a great opportunity for lasting peace and great prosperity and wealth. This missed opportunity is a truly sad moment in history.

Sincerely yours,

Donald J. Trump

    President of the United States of America

    A medical study has shown that excess(过度的)coffee drinking could cause heart attacks in people who do not metabolize(使新陈代谢)caffeine fast enough.

    The study, published recently in the Journal of the American Medical Association, says an enzyme(酶)that metabolizes caffeine in the liver works differently in some people, depending on the make­up of the gene(基因). People who have a slow version (版本)of the enzyme are at a greater risk(风险)of a heart attack when they drink more coffee. The risk had something to do with a person's age and how many cups of coffee he drinks.

    The team from the University of Toronto in Canada studied 4,024 people living in coffee­rich Costa Rica between 1994 and 2004, of whom half suffered non­fatal(非致命的)heart attacks. They found slightly more than half had the slow version of the gene, while the rest had the fast form.

    Two to three cups of coffee a day increased the possibilities of a heart attack by 36 percent for those with the slow­acting gene and four or more cups a day lifted it by 64 percent.

    But those under 50 who had the fast version of the gene had a lower risk of heart disease, even with four or more cups a day.

    Those with the fast­acting gene who drank two to three cups of coffee a day had 22 percent reduced possibilities of having a heart attack, but drinking four or more cups a day only lessened the risk by 1 percent. Scientists recommend limiting coffee consumption(消耗量)to within four cups a day.

    It happens from time to time: you feel terrible when you take your first bite of a certain food, but after eating more, you find yourself enjoying it. This is what is called an acquired taste. But why do our tastes change?

    The answer, according to a recent study presented at an American Chemical Society meeting in Boston, lies in proteins in our saliva (唾液).

    Most of us tend to think saliva, almost entirely made up of water, is “only a mouth lubricant (润滑剂) helping us to swallow food,” the New York Times said. However, it also contains many proteins, which can help break food down, protect our teeth and help in tasting food.

    To explain how these proteins affect taste, a team of scientists from Purdue University in the US invited 64 volunteers to drink a bitter-tasting chocolate milk three times a day for six weeks and rated their tastes at the same time.

    According to the research, the participants found a strong bitterness on the first day, but the unpleasant flavor came to decrease as time went on and finally disappeared.

    That is not all that was changing. A noticeable increase in the levels of proline-rich (富含脯氨酸的) proteins was found in the saliva samples of the test subjects in the research period. These proteins serve to reduce the bitterness we taste and improve our adaptation to this flavor.

    “We think the body adapts to reduce the negative feeling of these bitter compounds,” said Cordelia Running, a food scientist at Purdue University. “Saliva changes flavor, which in turn changes eating choices.”

    This change in taste not only makes the food tastier, but also helps people keep an appetite for healthy food whose flavor might otherwise keep them away.

    One day, these proteins may even be extracted (提炼) and used as a separate food additive that could help people stick to healthy food whose flavor they continue to dislike, researchers told Science Alert. And according to Running, even it doesn't happen, the idea that “maybe some little piece of your body is actually trying to help you” could really benefit some people. Let's wait and see.