1 . I think a close friend is someone you get on well with, who helps you when you have problems, who gives you advice, and who always has time for you. I didn’t use to have many close friends when I was at school because I was very shy, but now I have several. They are all women. I think it’s difficult to have a close friend of the opposite sex (异性)．

—Marie

I think a close friend is someone who you’ve known for a long time, and who you still get on with. They have similar hobbies to you so you can do things together. I’ve got three close friends who I was at middle school with and we often go out together (without our parents of course). We often go camping, play football, or walk outside in the open air.

—David

I’m not sure how to answer the question because I don't really have any close friends. I know a lot of people but mainly through work, and the social occasions (场合) when we meet are business dinners, things like that. I think if you come from a really close family, friends are a bit unnecessary. I like spending my free time with my family.

—Richard

For me close friends are the people you spend your free time with. I go out at weekends with a group of people, and they are all my close friends. They’re also people who live near me. I don’t think you can have close friends at a distance because you need to be able to see each other often. But I don’t think you need to be doing the same things. I mean I’m at school but none of my friends are.

—Anna

2 . It’s 3 o’clock and you’ve been hard at work. As you sit at your desk, a strong desire for chocolate overcomes you. You try to busy yourself to make it go away. But it doesn’t. Here is another situation. Perhaps you are not feeling well. The only thing you want to eat is a big bowl of chicken soup, like your mom used to make when you were sick as a child. Food cravings area strong desire for a specific type of food. And they are normal.

Scientists at the website How Stuff Works compare hunger and cravings this way. Hunger is a fairly simple connection between the stomach and the brain. They even call it simply “stomach hunger.” When our stomachs bur x up all of the food we have eaten, a hormone (荷尔蒙) sends a message to one part of the brain for more food, which regulates our most basic body functions such as thirst, hunger and sleep. The brain then produces a chemical to start the appetite and you eat. Hunger is a function of survival.

A craving is more complex. It activates (使活跃) brain areas related to emotion, memory and reward. These are the same areas of the brain activated during drug-craving studies. So, some scientists call food cravings “mind hunger.” People often crave foods that are high in fat and sugar. Foods that are high in fat or high in sugar produce chemicals in the brain. These chemicals give us feelings of pleasure.

In a 2017 study, researchers at Cambridge University found that “dieting or restricted eating generally increases the possibility of food craving”. So, the more you deny yourself a food that you want, the more you may crave it. However, fasting is a bit different. They found that eating no food at all for a short period of time lessened food cravings.

So, the next time you crave something very specific, know that your brain maybe more to blame than your stomach.

8 . Many hear endlessly how good exercise is for our health,but you might be surprised to know just how good.    1    

It helps you breathe better.

Frequent exercise improves the volume of oxygen you can use in your body.This is what makes you fit and the benefits aren’t limited to sport.    2     Attending some professional courses can build core strength and improve shape,and so strengthen breathing muscles. 

Physical activity enhances your mental health.

Doing something active releases “happy” brain chemicals that make you more positive.The more you do it,the better you’ll feel.But you do need to work up a sweat.If you’ve had a bad day,treat yourself to a little bit of exercise.    3    

    4    

The way your guts (内脏) feel often impacts on your mental and physical health.Walking,running and yoga strengthen abdominal (腹部的)muscles,increase the heart rate and encourage your muscles to move digestive waste through your body more efficiently and digest food more quickly.

Keeping active keeps you young.

There may not be an elixir (灵丹妙药) of youth just yet,but keeping fit comes close.Just 15 minutes of exercise a day for eight years can increase your lifespan by three years.The more you do,the longer you could live.    5     It can be low-intensity exercise—swimming,a long walk on a running machine at the gym,or a low-intensity workout via special APPs.

9 . A new study proves when their teenagers cut back on social media use, they seem to feel better about themselves. Helen Thai, a doctoral student in psychology at McGill University, conducted the study. She said the research came from her own personal experiences. “I couldn’t help but compare myself when I was using social media, making me unsatisfied with my self-image.” Thai says. Although she was aware that social media posts often presented images that can be unrealistic in real life, it still had a negative impact on her. So, Thai and a team of researchers decided to test whether reduced time on social media would increase self-confidence in body image.

They hired a few hundred volunteers, aged 14-18, all of whom had experienced signs of anxiety or depression, which could make them easier to be affected by social media. Half of the teens were asked to reduce their social media to 60 minutes a day for three weeks. The other half continued to use social media freely, which averaged about three hours per day. The researchers gave the teens surveys at the beginning and end of the study. It included statements such as “I’m pretty happy about the way I look,” and “I am satisfied with my weight.”

Among the group that cut social media use, the overall score on appearance satisfaction improved from 2.95 to 3.15 on a 5 point scale. “This may seem like a small change, but any change in such a short period of time is striking,” the authors say.

“This research showed promising results that weight and appearance confidence can improve when people cut back on social media use,” wrote Thai. Thai says it’s encouraging that teens were willing to cut back screen time, even for three weeks. It’s also worth experimenting this approach with other groups, such as people with or at risk of eating disorders.

10 . As AI art generators(生成器) take the world by storm, some people wonder if their works should count as art at all. The technology is still developing and has some wrinkles to iron out, which means there are indeed problems to consider alongside the incredible artwork a good artificial intelligence can produce.

Art is classed as the product of imagination, skill, experience, and emotion, usually meant to represent something for the public to enjoy. Artists spent time and effort putting their inner worlds onto these works. Machine intelligence also puts a lot of work into sorting through tons of data, linking someone’s prompt to datasets, and trying to represent it as best as possible. The difference is that the AI is driven by commands instead of an emotional desire to express itself.

AI painters can produce over 1,000 original works of art with every tap of the enter key on a keyboard. But a mass-produced print of the Mona Lisa is worth less than the actual Leonardo Da Vinci’s painting. Why? Scarcity — there’s only one of the original. Should anyone pay for these things? And if an artist puts AI masterpieces up for sale, what should the price be?

AI art involves a program mimicking(模仿)the work of existing artists to create a new piece according to the request of a human. But who made the artwork, the machine or its user? And can the original artists sue for copyright violation(侵权)? Such questions complicate the merging of artificial intelligence and the art industry, while fueling arguments against recognizing AI-generated art as marketable artistic products.

Once we’ve answered those questions, we can tackle the really big one: When an AI-generated painting wins an award, who gets the prize?