Alice Lewis is from America. She is a creative girl. She likes to invent—to think of new ideas for things that no one has made before, and then make them.

One day, Alice’s mother showed her an article which explained how difficult it was to get sick people through the countryside to the hospital in Africa. Alice wanted to help.

Alice knew that in North America, before there were cars, horses pulled heavy things on a travois（旧式雪橇）which was made of wood. Alice thought people in Africa could do the same thing. She added wheels to the travois for the African people. To make her travois light to pull, she used bamboo, a plant that grows in Africa, instead of wood.

You need to wear a belt（腰带）to pull Alice’s travois. That means you can free your hands to carry or hold other things. Alice thought her travois was perfect for carrying food home from the market, as well as taking people to the hospital. After it was finished, she wrote instructions for building one. So people in Africa could make it by themselves.

Alice doesn’t know if she wants to be an inventor when she grows up, because she also likes music and writing. But she thinks it’s important for children to learn about inventing at school.

Have you ever heard about the whitest paint in the world? In September 2021, researchers at Purdue University in the US, had invented a paint that received a Guinness World Records for being the whitest in the world. But that isn’t the paint’s only special quality (特征).

The paint is developed by professor Xiulin Ruan and his team. It is so white that it could reduce (减少) the need for air conditioners. It works through a cooling technology that offers great promises to reduce space cooling cost and global (全球的) warming. “When we started this project seven years ago, we had saved energy and fought climate (气候) change in mind.” Ruan said in This Is Purdue. They wanted to invent a paint that would reflect (反射) sunlight away from a building, largely reducing the need for air conditioners.

In a report written by Ruan’s team, the researchers explain the white paint reflects up to 98.1% of sunlight, and sends infrared heat (红外线热) away from its surface (表面) at the same time. The paint takes in less heat from the sun than it gives out, so the outside of an object covered with this paint is cooled below surrounding (周围的) temperature without so much air conditioning. However, other paints get warmer rather than cooler. They reflect only 80%-90% of sunlight and do not have special qualities to make the outside of objects cooler than their surroundings.

“If you were to use this paint to cover a roof (屋顶) area of about 1,000 square feet, we think that you could get a cooling power of 10 kilowatts. That’s more powerful than the central air conditioners used by most houses, ”Ruan told in This Is Purdue. In other words, ______. The paint will probably help buildings depend less on air conditioning systems that are the cause of a part of the global warming.

You can’t buy the paint just yet, but researchers are working with a company to put the paint on the market. Someday we could cool our homes simply by painting our roofs with the whitest paint and it could help fight against climate change.

Do you play an instrument? Have you ever made one? Terje Isungset can answer yes to both questions. And he makes instruments out of something pretty cool. Ice!

Isungset got the idea for ice music more than 20 years ago. “I was asked to do a concert in a frozen water fall, ” he says. This gave him the idea to play instruments that were actually made out of ice. As far as he could tell, this hadn’t been done before. “There were no books to read about it-nothing on the Internet,” he says. “So I had to create everything by myself. ”

In 2006, Isungset helped start the Ice Music Festival. It is held in February. Almost everything at the Ice Music Festival is frozen. “As you can imagine, there are a lot of things to do, ” Isungset says. “We come to a place, we collect the ice, and we build the concert space out of snow and ice.”

For the festival Isungset has a goal of trying to invent a new instrument every year. He is going to play an ice horn (喇叭) this year. “Would your mouth stick to it? Many people ask that question, ”

Isungset says. “If the horn was made out of metal (金属), it would get stuck completely.” His solution? Use a small piece of leather (皮革) . Place it on the horn’s mouthpiece. “It’s the only part of my instrument that is not made of ice.”