Visiting a famous coffee house (Café) in Vienna (维也纳) is a must for every visitor. Coffee houses first appeared in the 17th century and they have remained popular because of their relaxed atmosphere (气氛). It's completely normal for a customer to stay there alone for hours and read the newspaper. The waiter will always serve a glass of water with your coffee and, if you stay for a long time, they will bring you more water from time to time. The idea is that you are a guest who should feel welcome.

So, which coffee house should you visit?

I couldn't have a happy summer holiday anymore! No sleeping in. No games. No Internet. My parents gave me a big speech. And then they sent me to a classical music camp. Help!

The first day was scary. A boy asked about my favorite composer (作曲家). Composer? I didn't know any. Everyone played classical music, but I played electronic music from my computer. It was an electronic remix (a mix of different songs) I made. Nobody said anything. The teacher, John, said it was good, but I wasn't sure.

The next week was worse. I tried every instrument. The violin sounded like a crying cat. The tuba made no sound. The kids laughed at me. I didn't think I'd survive.

But something changed. John played a piece of music for me. It was amazing. "Beethoven (贝多芬)," he said. He suggested doing a remix of a classical Beethoven piece and presenting it to the other kids. I accepted the challenge.

When I played my remix, I was nervous. What if the kids said that boy wasn't playing "real music"? What a surprise! They liked it.

With their help, I chose another Beethoven piece. We decided to remix it together. During the following two weeks, we practiced every day. How crazy! One kid even gave me a piano lesson.

On the last day, we performed for the parents. I started the remix. The other kids joined in. When we finished, everyone cheered. Dad was smiling. Mom was crying. Beethoven and electronic music were a great match!

Scientists tell how healthy rainforests are by listening to the sounds of their wildlife. A healthy forest is alive with animal calls and birdsong but an unhealthy forest is much quieter. However, that is a big job. Researchers can make thousands of hours of recordings but then someone has to listen to them all and pick out the different animal and bird calls.

What if that someone is an AI though? Scientists are using AI technology to help with the task. Through the new Forest Listeners web experiment, scientists want people around the world — including you — to help too.

The site gets you to move around a virtual (虚拟的) forest, listening for wildlife. When you find a new species (物种), you listen to its song until you can remember it. The next step is to listen to real forest recordings (there are more than 1.2 million of them), and decide for each one whether you can tell that animal call or not, or if you're not sure.

The answers people give are then used to train AI to tell what animals they are by their sounds. Scientists say that the project helps them process a huge number of recordings. Without AI, it would take many years to study them all. "Every sound tagged (贴标签) by a forest listener helps train our AI models," the scientists said. "This group effort provides us with valuable information, allowing us to find out small changes in species' presence and behavior. These are important signs for a healthy forest."