Whenever we meet new people, we try to leave them with a good impression. First impressions are the judgments (判断) we form about others when we first meet them.

Oftentimes, we make judgments by people’s appearances. We usually think that a person who is wearing smart clothing is more polite than a person who is dirty and untidy. Besides our sense of sight, our sense of smell also helps. We prefer to be around people who smell familiar to us. This is a sign that they are like us and can provide us with more social help. In addition, our sense of hearing plays a role too. From the first word we hear a person speak, we start to form an impression of that person’s personality.

How long, then, does it take to form a first impression? Scientists at Princeton University showed pictures of unknown faces to a group of people for one tenth of a second, half a second, or one second. These people were then asked to immediately judge these strangers by answering several questions, including “Does he/she look knowledgeable?” “Do you think he/she is trustworthy (值得信赖的)...” According to the experiment, there was almost no change in judgment after the first tenth of a second. So scientists thought that it only took 0.1 seconds for us to form a first impression.

Even though first impressions are formed within such a short period of time, studies show that they can continue to have an influence for several months. Of course, sometimes you may fail to make a good first impression on others. Luckily, their impression of you is not set in stone. Just like anything else, they can be improved over time through your efforts.

“WHAT CAN I HELP YOU WITH?” says a voice from an iPhone. It’s Siri, and she’s ready to follow your voice orders to search the Internet, text someone, or play a song.

Siri is an example of artificial intelligence (AI，人工智能), or a computer program that can think. The way Siri thinks is very different from how a person thinks. She doesn’t have a brain. Instead, she depends on code (编码) in a computer program to understand speech and answer questions. And some questions are still too difficult for her to answer. But AI programs like Siri are getting smarter each year. In 2011, an AI named Watson beat two human champions on the show Jeopardy! Computer programs can also drive cars, do science experiments, and produce their own artwork.

Someday, artificial intelligence can probably surpass human intelligence. Once this happens, computers will think, plan, and act in a way that human beings can’t understand. In the book Superintelligence, Nick Bostrom thinks if a superintelligence wanted to control the world, it would easily do so. It could even make all humans die out. Whatever it did, we would lose our control over the world. He’s not the only one worrying. In 2015, a group of great scientists, including Stephen Hawking, wrote an open letter to remind (提醒) people to do the AI study more carefully. AI can surely make our society better, but it must do what humans want them to do.

However, if people do create a super AI, how will we be able to control it? What will happen to us if a super smart AI starts making decisions on its own?

I had been skiing since childhood. I had hardly fallen. I had never crashed into anything, and I’d skied mostly on the “blue” trails—the ones for intermediate (中级水平的) skiers. For this season, I decided to take a blue run, one I had done many times before. But whenever I reached the top, I started to slow down. Why did the blues look so...vertical (垂直的)? Were they always like this?

Simply having skied “many times before” didn’t mean I was getting better at it. Practice doesn’t always make perfect. Getting better or learning means doing different types of tasks instead of repeating the same mistake. With skiing, rather than just doing that same “blue” over and over again, we should go to different hills, trying different trails. The joy of getting better comes after the pain of getting worse.

One afternoon, I met a ski coach named Bob. When I told him my problem, he offered to watch me practise once, to see what I was doing wrong. Bob told me that the learning process isn’t always an up or forward improvement. When babies first learn to talk, they do it by copying adults. As they learn to talk about something in the past, they add an “-ed” to the end of a word. They might say something like, “We goed to the library today.” Though that’s not correct in grammar, the baby progressed from copying to using one of the rules of grammar. Adults do this, too.

Bob skied with me a bit more, until I had completed enough turns to make him feel like his volunteer-coach time wasn’t wasted.

“You’re skiing better already, young man!” he said.

“Thank you!”

Then I skied a few more feet and fell.

I recently planned a coach trip to London for my dad and myself. And that day in August of last year was     41     (real) bright and warm.

We were taken first to Greenwich where my dad had grown up. It was so much     42     (clean) than he remembered and, of course, there were many changes, mostly for the better. Alongside the National Maritime Museum we stopped     43     a coffee in a lovely open air café with views over the River Thames.

Soon we     44     (call) by the guide to join a “city cruiser”, together with other members of the trip. Once we set sail, the first famous building we could see was Queen Anne’s House     45     is set at the foot of the Royal Greenwich Park. We spent the whole time sitting on the top deck (甲板) and enjoying the many sights     46     we were sailing slowly.

The final destination (目的地) was the London Eye. Our prepaid tickets meant that we didn’t have to stand in line with the other     47     (tourist). We looked out over the whole city,     48     (include) Big Ben and the Houses of Parliament. We could even see Buckingham Palace in the distance.

Upon leaving the London Eye, we only had to take     49     short walk across the park to where our coach was waiting to take     50     (we) back. Our trip to London proved to be a quite lovely and memorable day out—my dad especially enjoyed every minute of it.

World Mental Health (WMH) Day is on 10 October. It was created to make people pay more attention to mental health, fight against stigma (羞耻) and support people with mental health problems. Read the following to learn more.

Tip 1 Everyone needs time alone sometimes, but it’s healthy to communicate. Spend time together with people you like, trust and who make you feel good. If you feel lonely, try volunteering. It’s a good way of meeting new people, and you’ll feel good about helping others.	Tip 2 Your diet can also change how you feel. If you eat a lot of cake or chocolate, your blood sugar (血糖) will rise and fall, which could make you feel angry or tired. You should eat enough vegetables and fruit, or you may miss what your body and brain need to make you feel well. Drink enough water too. It can make you think clearly.
Tip 3 Most people know that exercise is good for your body, but did you know it’s good for your mental health too? Often doing exercise can make you less worried and stressful. Why not exercise by going for a walk in the park or countryside? Spending time in nature also makes people relaxed.	Tip 4 Social media can be interesting, but it may also trouble you. Remember that people’s messages and photos are only the things that they want to show you, they don’t show you their bad days or worries. Always stay away from anything unpleasant, and check how long you spend online and keep it under control so that you enjoy your offline time too!
About WMH Day World Mental Health Day, on     51    , is a day to make people pay attention to     52     problems around the world. What can we do? Tip 1: Spend time with others Tip 2:     53     Tip 3:     54     Tip 4: Keep social media under control Think of one more tip:     55