1 . Life on earth evolves (进化) through the passing on of genes. How does culture evolve?

The evolutionary biologist, Richard Dawkins, coined the term “meme” in his book The Selfish Gene. According to Dawkins, while genes are the pieces of biological information from our parents which determines our appearance and how we grow, memes are units of cultural information — ideas and beliefs — that “pass from brain to brain”. Like genes, memes must compete for survival — if a meme cannot gain our attention. it disappears.

Basically, any shared idea related to culture is a meme. Myths, for example, are memes. Every society has its own stories that have survived, with some variations, for hundreds or thousands of years. The mythological dragon in Chinese culture is an idea that has been successfully passed among people for generations and is therefore also a meme.

Historically, memes have spread very gradually by word of mouth. Within Internet culture, though, a successful idea can be shared among millions of people within a few hours. Internet memes (which may for example, take the form of an image, a video or a website) may not last long, but they are particularly catching. They are shared “liked” copied and thus rapidly grown.

Then why do some ideas succeed in gaining our attention while others fail to attract us? It’s difficult to say, but humor is generally a factor. People are most likely to forward something to their friends if they think it is funny and the easier it is to digest the further the meme travels. Other memes may gain ground because they are something out of the ordinary. Aside from pure entertainment. Internet memes have a commercial aspect. Given their mass appeal, it is no surprise that advertisements turn up alongside them.

2 . Fast walkers may live longer than dawdlers (缓慢的人)— regardless of their weight, a new study suggests.

Researchers at Leicester University analyzed data on 474, 919 people with an average age of 52 in the UK Biobank between 2006 and 2016. They found women who walked briskly had a life expectancy of 86.7 to 87.8 years old, and men who kept up the pace had a life expectancy of 85.2 to 86.8. Slow walkers hadn’t much encouraging prospects (前景): women had a life expectancy of 72.4, and men of 64.8 years old, if they were more leisurely in their movements. According to the paper, published last week, that ratio held true even if the fast walkers were severely overweight. It does not necessarily mean fast walkers will live longer. Experts say it suggests walking speed could be a simple way for doctors to judge their patients’ general health alongside other tests.

It is hardly the first study holding up walking speed as a powerful evidence that appears to improve and determine our health.

In 2011, the Journal of the American Medical Association (JAMA) published a study by Stephanie Studenski, who found the same: walking speed was a reliable predictor of life expectancy.

In 2013, US researchers found walking pace was linked to lower heart disease risk and longer life expectancy. In 2018, a study from the University of Sydney found picking up your walking pace to even an “average speed” could cut your risk of premature death by a fifth.

And Tom Yates, the physical activity professor at Leicester who's behind the latest study, has been publishing findings on this connection for years.

In 2017, he analyzed the same UK Biobank data and found walking speed appeared to affect the risk of dying from heart disease — concluding that the slowest walkers were twice as likely to suffer a heart-related death compared to quick walkers.

4 . China has announced that couples will be permitted to have up to three children in a major policy shift from the existing two-child limit, after recent data showed a dramatic decline in births in the world's most populated country.

"To actively respond to the ageing of the population…a couple can have three children," state media Xinhua reported on Monday, citing a committee meeting hosted by President Xi Jinping

Early this May, China reported the slowest population growth since the early 1960s, despite scrapping its one-child policy in 2015 to encourage more births and avoid a potential population crisis.

A once-a-decade survey showed that the overall population of China grew to 1,41178 billion in the 10 years to 2020, up by 5. 38%. The increase reflects an average annual rise of 0.53%, down from 0.57% reported from 2000 to 2010.

The announcement drew a chilly response on Chinese social media, where many people said they could not afford to have even one or two children. "I am willing to have three children if you give me 5 million yuan (£554,350)," one user posted on Weibo. As a matter of fact, experiment of the three-child policy in Heilongjiang province in the last few years also resulted less effectively than expected.

It is not only China that is facing such a population challenge. Across east Asia, authorities have, for years, been struggling to persuade couples to have more babies. South Korea and Japan both have used allowance to encourage.

The policy change will come with "supportive measures, which will be beneficial to improving our country's population structure, fulfilling the country's strategy of actively coping with an ageing population and maintaining the advantage of human resources", Xinhua said. It did not specify the support measures.

6 . As a middle schooler, one of my life goals was the Presidential Fitness Award-an honor given to those who passed a series of gin-class tests that included doing a number of pull ups, running a mile, and, among other things, the sit and reach(another version of toe touching). That's where things went wrong for me. I could never reach quite far enough.

Toe touching is an easy way to begin or end any sort of workout, For most people, it is among the easiest stretching exercises to do. But for me(and any of my classmate)it's complete suffering. Why? “The two biggest factors are the flexibility of your hamstrings(腿筋) and the range of motion of your hip(髋) joints,” says Jeffrey Jenkins, a physiologist at the University of Virginia School of Medicine. “But another big factor is the relative length of your arms and your torso(躯干) to your legs, which unfortunately can't be changed.”

Ienkins says that although there are sore unjust aspects, overall the toe touch is not the worst measure of flexibility. But if you are flexibility clumsy like me, there are some things you can do to improve the flexibility of the body you have. Whenever you stretch then, your muscles contract, tighten, and resist the force to be stretched, resulting in that annoyingly painful feeling that most of us get when we first reach down to touch our toes or attempt to stretch other muscles. However, Jenkins says, if you are patient, this too shall pass.

If you hold the stretch for a minimum of six seconds, you can actually overcome the re flex (反射). In fact, Jenkins says, there's some evidence that holding still stretches for 30 seconds results in greater improvement in flexibility than holding it for 15 seconds, and just as much improvement as 60 seconds. But for some people, the pain that accompanies those sixty seconds is just too severe. If you can get past that pain, then you can probably improve your flexibility However, Jenkins cautions against tolerating too much pain; you could be tearing a muscle.

8 . “What is the story of your piano?” a new friend asked over dinner. My piano sits in the corner of my small living room.

My piano has a story? “All pianos have stories” she said. Suddenly, my piano’s story came flooding out of me fully-formed as if I’d always had this tale to tell.

I loved music since childhood. I started with the recorder and moved on to instrument like the violin, trumpet (小号) and guitar. But playing the piano had always been my dream, a dream our family could not afford.

I grew up in an immigrant Chinese family in Toronto. My father waited tables in a Chinese restaurant, and my mother worked in a Chinese laundry. Despite our poor childhood, my siblings (兄弟姐妹) and I were always fed with love. I can’t remember which birthday it was when she spared the money to buy me a doll. Of course, by then I’d grown out of the age of wanting dolls, but she worked too hard to know that, and I never told her. I happily and gratefully accepted the doll because I loved the gift that was her loving me enough to buy it for me.

So it was eventually with my piano. It was in my last year of high school. I took piano lessons for about a year before university forced me to stop. I had to make a decision: to work towards the more practical goal of medical school or my love for music. Finally I chose to stop piano lessons.

I moved that piano around with me over the next decade — until my son was born. He showed an early interest in music, so I put him in piano lessons. I played that piano through my son — although guitar was finally his instrument of choice .

I’ve come to realize that for my career, I’ve let all personal pleasures fall away. I figured I’d get back to playing the piano when I retire. Maybe it’s time to get that piano retuned (重新调音) again, this time for myself, before it’s too late to enjoy. Maybe that’s something we all should do right now .

Sometimes a single question can open whole paths of thinking and discovery. So, what is the story of your piano?

10 . Which is better for Earth: an electric or gas-powered vehicle? The answer to this question might seem blindingly obvious. Of course electric cars must be better for the environment, because they don’t give off greenhouse gases as people drive. However, electric vehicles (EVs) aren’t perfect, and they come with their own set of polluting problems. Their batteries require a large amount of energy to produce.

Battery production is just one part of an electric car’s life span. A study looked at the entire life cycle of an EV’s emissions(排放)，from mining the metals for the batteries to producing the electricity needed to power them, and then compared this with the average emissions of a gas-powered vehicle. The team found that when EVs are charged with coal-powered electricity, they’re actually worse for the environment than gas-powered cars.

“Only when connected to the clean energy do EVs have an advantage over the gas-powered cars on a greenhouse gas basis,” said Colin Sheppard, an expert in energy and transportation systems. That’s why more and more countries are decreasing the power supply from coal. In China, the national grid is improving with more efforts in renewable energy. For example, it has twice as much wind energy capacity as the U.S. and it builds more solar panels per year than any other countries.

Sheppard has modelled a future in which all cars are electric. “We want to understand what it might be like if all passenger vehicles were electrified.” The model suggests that if all vehicles in the U.S. were electric, greenhouse-gas emissions would be 46% less every year. This reduction could be increased even further if those vehicles were using a technique known as “smart charging” in which cars are recharged at chosen times (often at night) to reduce the cost of electricity.

In short, it’s far easier to argue for buying an EV than a gas-powered vehicle. But what about the cost? Aren’t electric vehicles too expensive for most people?