4 . It was the homecoming parade in Rockwall, Texas, and cheerleader Tyra Winters was riding on one of the school’s floats (彩车). As it slowly made its way down the avenue, the 17-year-old enthusiastically waved at the crowd, all the while absorbed in the music, laughter, and applause.

Suddenly, a terrible scream came from the cheering crowd. Looking down, Winters saw a two-year-old on the sidewalk gasping for air and his mother desperately begging for help. The boy had been enjoying a piece of candy when it slid down the back of his mouth, sticking in his throat and blocking his windpipe (气管).

“I saw a little bright red face and his mom’s begging for help,” Winters told KTVT.

“There was no coughing; there was no breathing,” the mother, Nicole Hornback, later told news station NBCDFW. “He was just gasping for air. ” No one seemed to know how to help.

Except for Winters. A senior with dreams of becoming a doctor, she had learned the first-aid method of Heimlich maneuver and CPR. Knowing that the clock was ticking, she jumped off the moving float and ran to the child. By the time she got to him, his face had turned purple. “I got him!” she yelled to Nicole as she grabbed the boy from her. “I held him face down and gave a good three back pushes,” she told the local CBS station. Soon, the boy coughed up the piece of candy, and began breathing again. Without another word, Winters handed the boy back to his mother and ran back to her float before it could leave her behind.

It all happened so fast. Nicole never had time to thank the teen. “She didn’t need to,” says Winters. “I knew how she was feeling. I saw her tears. I saw her face. ”

And for Nicole, she says, “I don’t really have any words,” she says. “The words that you would say to anyone who does something for you is ‘thank you. ’ But that doesn’t seem good enough. ”

5 . Do you love food? Whether you’re a foodie or someone who just likes eating, there is so much to choose from. We know that too much of the wrong kind of food can be bad for our health, but for some people having a food allergy means eating certain things can actually be harmful — and now, it seems, this is affecting more and more of us.

An allergy is caused by the immune system fighting substances in the environment, known as allergens(过敏原), which should be seen as harmless. Food allergies can cause life-threatening reactions, which means people have to spend their lives following strict dietary restrictions and worrying about the ingredients of everything they consume. Allergy specialist Dr Adam Fox says, “If you look back over, say, 30 or 40 years… there are much more allergic problems around now than there were.”

We often hear about people having allergies to dairy products and to peanuts. Last year a young girl died after suffering a deadly allergic reaction from eating a baguette containing sesame seeds. This led to a call for better food-labelling laws.

Research has found that this problem is particularly affecting children. More and more of them are having allergic reactions to certain foodstuffs. Dr Alexandra Santos from King’s College London says “food allergy now affects about 7 percent of children in the UK and 9 percent of those in Australia. Across Europe, 2 percent of adults have food allergies”.

So what might be the cause? Dr Santos says the increase in allergies is not simply the effect of society becoming more aware of them and better at diagnosing them; it seems to be more environmental. She says possible factors are “pollution, dietary changes and less exposure to microbes (微生物), which change how our immune systems respond”.

A lot of work is being done to try and find a cure, but that’s not easy. So for now allergy sufferers must watch what they eat and they must rely on clear and accurate labelling.

6 . What do extreme marathoners, mountain hikers and professional bicycle racers all have in common? They push their bodies to unsustainable (不可持续的) extremes of physical stress.

We tend to think there’s no limit to human physical achievements. But a new study, published in Science Advances, says there is a definite limit to human endurance (耐力). Beyond that, our bodies begin to break down.

To find the limit, a US research team tracked marathon runners over a five-month period, measuring competitors’ initial basal metabolic rates (BMR, 基础新陈代谢率) – the amount of energy they expend when they rest. Then they looked at how many calories(卡路里) each runner burned per day.

The team found that the maximum amount of energy a human can expend is 2.5 times of BMR. It equals 4,000 calories of energy per day. These calories can help a trained athlete to run about 42 kilometers in a day.

But people can’t keep using this amount of calories all the time. “You can do really intense stuff for a couple of days, but if you want to last longer then you have to dial it back,” US evolutionary anthropologist Herman Pontzer told the BBC.

Pontzer explained that the problem is our guts (消化道). “There’s … a limit to how many calories our guts can effectively absorb per day,” he said in the Daily Mail. At that point, the body is burning calories more quickly than it can absorb food and convert (转化) it into energy.

These new findings could help athletes to best work underneath this ceiling. For example, they could manage their daily exercise time based on their BMR, to get enough calories and keep going.

However, Pontzer’s team can’t rule out the possibility of someone breaking this limit. “So I guess it’s a challenge to elite endurance athletes,” said Pontzer. “Science works when you’re proven wrong. Maybe someone will break through that ceiling some day and show us what we’re missing.”

7 . COURTESY PAUL BOZYMOWSKI-Three New York City police officers paid for a woman’s groceries rather than arresting her.

As temperatures approached 90 degrees in New York City last July 4th, three police officers ducked into a Whole Foods Market to get something cold to drink. What they walked into was a heated human drama.

Once inside, the cops, Lt. Louis Sojo and Officers Esanidy Cuevas and Michael Rivera, were approached by a store security guard who asked for help with a suspected shoplifter. The woman in question didn’t have the look of a career criminal. She was obviously scared, and her cheeks were wet with tears.

The cops peeked inside her bag. “All we saw was containers of food.” Cuevas told CBS New York.

"I’m hungry," she explained quietly.

Caught red-handed, the woman no doubt expected to be sentenced to jail for the crime of being hungry while poor. But the cops had other ideas. “We’ll pay for her food,” Sojo told the surprised security guard.

There’d been no discussion among the three men. It went unsaid. Instead, they picked up the woman’s bag and accompanied her to a cash register, where each took out $10 to pay the tab. She would not be arrested today.

All the woman could do was weep in gratitude. Covering her face with a kerchief and drying her eyes, she repeated, “Thank you, thank you.”

She wasn’t the only one touched by this act of mercy. “It was a very beautiful, genuine moment,” says Paul Bozymowski, who was at the store. He was so taken by what he’d witnessed that he posted a photo on Twitter for all to see.

But attention was never what the officers sought. They were driven by a far more common emotion. As Sojo told CNN, “When you look at someone’s face and see that they need you and they’re actually hungry, it’s pretty difficult as a human being to walk away from something like this.”

8 . Ever since Donald Trump was elected the president of the US, the entire Trump family has been put under a microscope. In China, the spotlight has been mainly focused on Trump and his daughter Ivanka. She is described on WeChat as an extremely influential role model with stunning beauty, a successful career, and a happy family. She leads a dream life that a million girls would kill for. Yes, she was born with a silver spoon in her mouth. But she got where she is by herself.

There are always articles that say people born into wealthy families are better looking and have a better family background than you, but these people do work harder than you. Are you a loser if you were raised in an ordinary family? Should you feel guilty that you sleep eight hours a day because Ivanka sleeps five?

If you just want to keep a stable nine-to-five job, does it mean you are not ambitious? How about if you don’t work out or eat healthy, does that mean you will not find your Mr. or Miss Right? There is a tendency in media nowadays to encourage elitism. They are trying to brainwash young people into thinking that they should invest a huge amount of time and money in bodybuilding and appearance enhancement so as to improve the quality of their life and join the elites. But what’s the disadvantage of being of average quality? Do you really need to go to the gym five days a week unless you are a gym maniac (狂人)? Do you really need to break your neck and sacrifice to earn your first pot of gold only to worry constantly about how to be accepted into high society later?

Don’t let the idea of elitism get to you. Everybody has a right to live the life they want. Human beings should not be judged as a success or failure based on whether they are a part of the elite or not. As long as you lead a happy and comfortable life, why bother to chase after other people’s shadows? Choose your own life path and go for it.

9 . “Shine in the dark” dolphins may seem like something straight out of a science fiction movie. However, that is precisely what Newport Coastal Adventures' Captain Ryan Lawler and professional videographer Patrick Coyne witnessed, when they set out to explore the spectacular blue tides that have been lighting up the waters off Southern California's coast since mid-April.

The partner scanned the ocean for hours and was returning to shore when they spotted the “electric” dolphins swimming through the bloom of shining plankton(浮游生物). The videographer, who had seen the phenomenon only once before in a Netflix show, says catching the scenes proved to be a lot harder than he had expected. “For starters, the shining plankton has sweet spots to where it shows up and then fades away, so while on the water, it's impossible to just find it,” Coyne says. “Also, conditions have to be absolutely perfect for the shining plankton to show and for animals to swim through it so we can film it.”

Though witnessing shining sea life is rare, the electrifying blue ocean scenery is a fairly common sight around Southern California between February and September. The phenomenon can be attributed to the presence of millions of plankton, which tend to gather and reproduce in large quantities in the warm coastal waters during this time.

Though a majority of California's red tides are caused by plankton species that do not produce deadly poison, some algal blooms(藻花)can be dangerous for sea animals, especially when they stay for long periods of time. In 2018, an almost year-long “red tide” along Florida's Gulf coast caused by the excessive growth of microalgae Karenia Brevis, killed hundreds of fish and other sea animals.

10 . Just before Christmas in 1994, a letter arrived at our house. The postmark was from Tuskegee, Alabama, so we all knew who it was from. We excitedly gathered around mother as she opened it.

       I didn’t get the leave I expected for Christmas. I’ll miss all of you. Please leave the Christmas tree up until I make it back. I hope to be home by March.

                                                                                          Love from your son,

                                                                                          Clifton

       My heart sank. I felt profound sadness that my favorite brother wouldn’t be home for Christmas. My mother, being the optimist she always was, said, “Well, it looks like we’ll get to have two Christmases this year!”

       After Christmas, my sister and I worked together to make sure we kept that Christmas tree looking as pretty as possible. This was no easy feat. By mid-January, the branches drooped so low to the ground. Each day, ornaments would come crashing to the ground and there were brand new sprinklings of pine needles all over the wooden floor. My sister and I took turns sweeping them up. We repositioned the ornaments to the stronger branches on the tree, hoping they would stay on.

       Each time we freshened that tree up, my sister and I were full of thoughts about Clifton and how happy we would be to see him again. It made us feel that he was close by, even though he was hundreds of miles away.

       On March 5, the doorbell rang. We ran to the door and gave Clifton a big hug. As he hugged mother, I could see him peek over her head at the Christmas tree.

       “It’s beautiful,” he said. “Thank you.” Clifton opened his presents and told us all sorts of stories about his work in Tuskegee. That night as we slept, we heard a crash in the living room. We all ran to see what had happened. The tree had toppled onto the sofa and there were needles and broken ornaments everywhere. We all had a good laugh. It was fortuitous (巧合的) Clifton got home when he did.