Billy always loved blueberries. They were his favorite fruit. Today he was going to make juice with his uncle. His uncle liked to make juice out of everything. He made carrot juice, apple juice, vegetable juice, and more juices. He had never made blueberry juice before though!

  First, Billy and his uncle went to a blueberry farm. They were each given a basket. They picked for an hour and got several pounds. It was hard work picking the little berries from the trees. Now Billy understood why they were expensive in the store.　

  Next, they had to wash the fruit. Some of them still had leaves. Those had to be pulled off. Then the bad berries had to be thrown away. They washed the berries and made them air-dry.

 After that, they pushed the blueberries through a strainer(过滤网). The strainer caught most of the seeds and skins, and only left a small glass of dark purple juice to them.

 When they tasted the juice, it wasn't very sweet. Billy's uncle didn't want to add white sugar to the juice. It was better to use a naturally sweet juice, like apple juice, pear juice, or grape juice. They used grape juice as a sweetener (甜味剂), because grapes had a similar color to the blueberries.

  Finally, they could drink it. It was a lot of work to make juice, but it sure was refreshing!

根据短文内容，选择正确答案。

    Kyle walked up and down as he waited for his turn at the back stage. This would be his most important piano performance yet. At ten years old, he was the youngest performer in the Christmas concert. Although his teacher Ms. Neal said he was good enough at the song he would play, he still practiced it more than 30 times that week. When he closed his eyes at night, the music played over and over again in his mind

    Now, the day finally arrived, but Kyle was not sure he was ready. He kicked a small ball which was picked up from a Christmas tree, and then looked himself in a mirror—trying to make his bow tie more smooth and beautiful. He thought of his mom who bought him the new suit with this bow tie. He would make her feel proud of him. He noticed that his hands were shaking. How could he play the notes of the song if his hands were shaking? He took a deep breath and tried to calm down, but his hands shook more.

At this time, Ms. Neal walked up to speak to him. “I have something for you,” she said, putting a smooth black stone into Kyle's hand. “It's a special stone. There's no other one like it in the world. You've practiced so much, so you don't need anything else.”

    The stage lights reflected on it. “Thank you.” Kyle said.

When Kyle's name was called, he rubbed the stone, stepped onto the stage, and played better than ever. After his performance, he noticed that Ms. Neal had a whole bag of black stones. “Why did you say this one was so special?” he asked.

His teacher smiled, “Like your talent, it is special because it belongs only to you.''

    I grew up in a small town in South Canada. Every autumn, there was a week—long fair in the town. Thousands of people from other towns came to sell and buy things. It was the most exciting time of the year.

    When “Fairtime” came, my grandma became the busiest person of the family. Grandma was a kind, well—educated old lady. She was good at cooking. During “Fairtime”, relatives would come to live in her house and have meals there. Grandma was always happy to look after them.

    Year after year, many people moved to big cities. There was no longer “Fairtime”. Grandma became very old and was going a little blind. My parents and I did our best to make her life as comfortable as possible. I was at high school then. What I often did at home was to help Grandma with the daily newspaper's crossword puzzle. However, she didn't look happy. She often sat in her room for hours, without saying a word.

    To attract people to move back, the Town Hall decided to reopen the Fair. One day, when I came back from school, I saw Grandma wearing her glasses, washing the dishes in the kitchen. With a big smile on her face, she looked excited and a lot much younger. She told me that her two of her cousins would come. "They said they missed hometown and wanted to enjoy my food again."  Grandma said happily. "They will stay here for one week and we can have a big party. That must be the busiest week I've had in years!”

    I suddenly realized that Grandma didn't want to be looked after. She wanted to be “useful”, appreciated and helpful.

    It was summer. A duck was sitting on many eggs in her house. Her little ducks were going to come to the world. One little duck after another came out from the eggs. The last baby was big and ugly. His brothers and sisters weren't willing to play with him because he was too ugly. Even his mother hated him too. And the girl who fed them kicked him.

    The poor little duck was so sad that he ran away from home in the winter. On his way, a big dog appeared, but the dog did not come close to him. "Oh, I am so ugly that even the dog won't bite me." the duck said to himself.

A kind farmer took him home when the weather got colder. He stayed there for a whole winter and left when the spring came.

    One day, he met three beautiful white swans (天鹅) when he was swimming in a lake. They swam toward him. He was afraid to make friends with them. But what did he see in the clear water? He was no longer a dark grey ugly duck. He was a beautiful swan himself. How amazing! He never dreamed that he could be so beautiful.

Young scientist Li Yuehua works at Zhejiang Lab(之江实验室) in Hangzhou, Zhejiang Province. There is something special about the lab— as Li enters it, she feels out of this world. It brings her to one of the earth's closest neighbors: Mars.

The lab simulates(模拟) the environment, such as the ground and light, on the red planet. In the lab, Li and her team develop and test AI technology to make future Mars rovers(火星车) smarter.

Zhurong, China's first Mars rover, got to Mars in 2021. As Zhurong moves on Mars, it sends information back to the earth. The ground team checks the information before it can move on. The process can take up to 40 minutes.

" Today's rovers are like babies. They can perceive what's around them but they're not able to understand them. Scientists on the earth must tell them how to communicate with the environment," said Li." We hope our AI technology will help Mars rovers learn about the environment and decide where to go on their own."

Li's team needed a better place to do that. Is there anywhere similar to Mars on the earth? The answer was found in the deep desert of Dunhuang, Gansu Province. The team went there in summer and soon started to work. However, it was so hot that several machines stopped working and some team members got sick. Although it was really hard, they didn't give up. Finally, the team developed a better technology.

" An important part of science is facing failure(失败)," Li said." It is like climbing. You face difficulties and try to solve them time after time."