In a historic moment on June 26, the US Supreme Court ruled that same-sex marriage is a legal right across all 50 states. The Supreme Court justices ruled states cannot deny gay men and women the same marriage rights. The decision means the 13 states with bans on same-sex marriage are no longer able to enforce them.

    Same-sex couples “ask for equal dignity in the eyes of the law”. Justice Anthony Kennedy wrote in the majority opinion: “The Constitution grants them that right.”

    The decision came after decades of litigation（诉讼） and activism. It set off celebrations across the US. In affected states including Georgia, Michigan, Ohio and Texas, same-sex couples rushed to wed, while officials in Mississippi and Louisiana said marriages had to wait until procedural issues were addressed, reported the BBC.

    According to “The New York Times”, the ruling came against the backdrop of fast-moving changes in public opinion in the US, with polls indicating that most Americans now approve of same-sex marriage.

    US President Barack Obama welcomed the ruling, saying it “affirms what millions of Americans already believe in their hearts.” “Today,” he said in a press release, “we can say, in no uncertain terms, that we have made our union a little more perfect.”

Another win.

    This was the second time the Supreme Court took up same-sex marriage, according to an article in “Business Insider”. The first time, in June 2013, the court made a decision that allowed the US federal government to recognize same-sex marriages in states where they were already legal.

    But at that time, the Supreme Court declined to rule on the broader question about gay marriage: Is there a constitutional（宪法的） right to same-sex marriage? The June 26 ruling gave a positive answer to that question.

Justice Kennedy wrote in the majority opinion that the Constitution should evolve with societal changes.

    “The nature of injustice is that we may not always see it in our own times,” he wrote. “The generations that wrote and ratified the “Bill of Rights” and the “Fourteenth Amendment（修正案）” did not exactly know the extent of freedom in all of its dimensions, and so they hoped the future generations can protect the right of all persons to enjoy liberty as we learn its meaning.”

    The Fourteenth Amendment addresses citizenship rights and equal protection of the law. In the June 26 ruling, the Supreme Court declared that the equal protection clause of the amendment requires marriage rights be extended to same-sex couples, too.

    On a Sunday morning, I was driving down a road and saw something I couldn't believe. A little girl, less than two, was pushing her stroller (婴儿车) across the road. It was Sunday morning and traffic was not heavy.

    I stopped my car at once and ran toward her. This little girl knew enough to run from a stranger. I tried to catch her in order that I could get her out of the road. Suddenly her father came running down a hill across the road from where I had parked my car. He ran right to her and caught her up, saying “bad girl” to her. I picked up the stroller and gave it to him. The father grabbed（抓住） the stroller and walked toward where he came from without a word. I went back and sat in my car for a few minutes with my son. My hands were shaking and tears were about to run out of my eyes. “Do you feel cold, Mom?” asked my son. I just shook my head.

    After this happened, I thought about how thankful I am. Even though the father didn't say thank you, I feel that I did something good. Doing something for someone else is pleasing, even when it's only a matter of being in the right place at the right time. I didn't really “save” her, but I feel like it was important that I happened to be there. It is sad that I was the only one who stopped. It really made me a little disappointed that no one else stopped to help.

    Exercise is known to benefit people's mental health, but scientists recently discovered that too much exercise may have a negative effect on it.

    The researchers studied about 1.2 million people in the United States in 2013, 2015 and 2017. The participants, on average, experienced 3, 4 days of poor mental health each month. Those who did exercise experienced 1, 5 fewer days of poor mental health per month, compared to those who didn't exercise at all. The team found that people who exercised for 30 to 60 minutes three to five times a week had the best mental health, but those who exercised for more than three hours had worse mental health than those who didn't exercise at all.

    The scientists think that people who exercise so much may experience poorer mental health because that much exercise can be a sign of obsessive (强迫症患者) behaviors that have been associated with poor emotional and psychological outcomes. However, the only mental health disorder that the researchers looked at was depression.

    Among those who had been diagnosed with depression, people who did exercise experienced 3.75 fewer negative mental health days than those who did not, showing an ever greater difference, According to the Centers for Disease Control and Prevention. 7, 6 percent of people in the U.S. age 12 and over have depression. While all types of exercise appeared to help with mental health, cycling, gym-based exercise and team sports were the most beneficial.

    The team also looked at more specific factors, like education. People with a college education reported 17.8 percent fewer days of poor mental health than those without that level education Additionally, people in a healthy BMI (体重指数) range reported a 4 percent reduction in poor mental health days thin those whose BMIs were high. Even salary was a factor: compared to people with bower salaries, those with higher salaries experienced a 17 percent reduction in poor mental health days.

    The study showed that exercise can help with mental health, but that in some cases, limiting it may be necessary.

    A long-term American study shows the importance of early education for poor children. The study is known as the Abecedarian(初步的) Project. It involved more than one-hundred young children from poor families in North Carolina.

    Half of the children attended an all-day program at a high-quality childcare center. The center offered educational, health and social programs. Children took part in games and activities to increase their thinking and language skills and social and emotional development. The program also included health foods for the children.

    The children attended the program from when they were a few weeks old until the age of five years. The other group of children did not attend the childcare center. After the age of five, both groups attended public school.

    Researchers compared the two groups of children. When they were babies, both groups had similar results in tests for mental and physical skills. However, from the age of eighteen months, the children in the educational child care program did much better in tests.

    The researchers tested the children again when they were twelve and fifteen years old. The tests found that the children who had been in the childcare center continued to have higher average test results. These children did much better on tests of reading and mathematics.

    A few years ago, organizers of the Abecedarian Project tested the students again. At the time, each student was twenty-one years old. They were tested for thinking and educational ability, employment, parenting and social skills. The researchers found that the young adults who had the early education still did better in reading and mathematics tests. They were more than two times as likely to go to college or to have completed college. In addition, the children who received early education were older on average, when their first child was born.

    The study offers more evidence that learning during the first months and years of life is important for all later development.

    The researchers of the Abecedarian Project believe their study shows a need for lawmakers to spend money on public early education. They believe these kinds of programs could reduce the number of children who do not complete school and are unemployed.

    There's a good chance something you've bought online has been in the hands of a "picker" first. These are the workers in warehouses(仓库)who pick, pack and ship all those things we're ordering.

    At Amazon and other companies, they're working side by side with robots. Experts say while the robots are replacing some human workers, the machines aren't quite ready to take over completely.

    When a robot finds its storage unit, it slides underneath, lifts it up and then delivers it to a worker 一 they're called pickers. On a recent day, the computer told a picker to grab what looked like a fantasy board (棋盘)game. The picker found it, canned it and placed it on the conveyor belt.

    ^"In a traditional fulfillment center where the associate would walk to the different items, it can take hours to fulfill a customer order." Robinson says.

    Now, with the help of robots, that task takes minutes 一 and fewer humans.

So is this a sign we're entering a new industrial revolution?

    "It's definitely going to take over a lot of jobs." says Karen Myers, a scientist at SRI, one of Silicon Valley's oldest research centers.

    At the same time, she says, we're running against the limits of technology. Take "the picker" at the Amazon fulfillment center. Myers says those skills are proving to be uniquely human.

    "Our fingers are incredibly flexible and the current generation of robotic operators, they're getting much_, much better," she says. "But they're just not quite there yet."

    There's also the robot's brain.

    Remember that board game the Amazon worker was looking for? She could barely see the box filled into the storage bin — but she could tell it was a board game. Robots can't do that.

    Technologists say that, increasingly, humans will work side by side with robots — instead of robots working alone.

    Amazon says robots and humans enabled the Tracy warehouse to fulfill customer orders faster. That means more customers and more human workers.

    Learning is so complex that there are many different psychological theories to explain how people learn. A psychologist named Albert Bandura suggested a social learning theory which shows that observation, imitation (模仿), and modeling play a primary role in this process.

    In Albert Bandura's opinion, people can learn through observation. Observational learning doesn't even necessarily require watching another person join in an activity. We can also learn by reading, hearing, or watching the actions of characters in books and films. However, just observing someone else's actions isn't always enough to lead to learning. Your own mental state also plays an important role in determining whether a behavior is learned or not. In addition, though in many cases, learning can be seen immediately when the new behavior is displayed, yet sometimes we can learn things even though that learning might not be immediately obvious, which means people can learn new information without showing new behaviors.

    Not all observed behaviors are effectively learned. Certain requirements need to be related to the observational learning process. For example, you need to be paying attention. Also your retention is an important part of observational learning as you need to pull up information later and act on it during the process. Once you've paid attention to the model and kept the information, it's time to actually perform the behavior you observed. Further practice of the learned behavior leads to improvement. Finally, you have to be motivated to imitate the behavior that has been modeled.

    Social learning theory have many real-world applications. For example, researchers employ it to look into and understand ways that positive role models can be used to encourage desirable behaviors. Besides, it's also applied in the field of education, and today, both teachers and parents recognize how important it is to model appropriate behaviors.