Students at Bullock Creek High School in Midland, Michigan found an unusual way to raise money for their robotics team.

Every year, 28 students on the Blitz Creek team take part in a national robotics competition, where students are challenged to create a robot that can perform certain tasks. They design robots, and write the programs that run them.

But building robots isn’t cheap. Maxton Herst joined the team in the ninth grade, and later he became the captain of the robotics team. By accident, Maxton Herst saw a video about a toilet paper pyramid. Maxton realized that it was possible to build a record-setting pyramid, and then sell the toilet paper to get money for their program. All the team members agreed to try his idea.

Blitz Creek has been planning the pyramid since last May. One challenge was calculating (计算) how many rolls of paper were needed. The answer turned out to be 27,434.

In late December, team members gave up part of their winter holiday to build the pyramid. The pyramid was so big that they had to build it from the inside before backing out and filling in the areas where they had been standing. It took about 16 hours, with many people working, which is about 61 centimeters taller than the current (当前的) Guinness World Record.

The pyramid opened for viewing on January 4, 2020. Sadly, because the pyramid was in the school’s front hall, it could only stay for three days. With all the excitement caused by the pyramid, it turned out to be fairly easy to sell the toilet paper. Many supporters did help. Families and teachers bought half of the paper. A large company bought the rest. The team made about ＄10,000 from the event, which will help pay for its activities.

Maxton talks about the success of his crazy idea. “If you’ve got an idea, and you know that this idea is good, push it,” he says. “Don’t stop.”

Are you nearsighted (近视的)? Do you wear glasses? Many of you may say “yes”.

In fact, China’s young people have the highest rate (率) of nearsightedness in the world. More than 70 percent of middle school students in China are nearsighted.

In August, a plan to solve this problem was introduced. It aims to cut down the rate of nearsightedness for middle school students to less than 60 percent by 2030. Schools across the country are taking action to meet this goal.

Luoyang Experimental School in Henan started with its desks. It has designed (设计) desks with a board above the desktop (桌面). The board stops students from lowering (降低) their heads too close to their desktops. More than 400 students have used them so far. More students will use them soon. Similarly, the High School Affiliated (附属的) to Renmin University Chaoyang Branch School is now providing desks and chairs according to students’ heights. Studies have shown that proper desk height can prevent (预防) nearsightedness.

Spending more time outside can also reduce (减少) nearsightedness. The Yucai middle School makes sure that its students play outside for at least 80 minutes every day. We have a P.E. class and a 20-minute break in the morning and afternoon to do exercises, "said Sun Zihan, 14.

Staring at screens can also hurt our eyes. Beijing 101 Middle School has a solution to this problem. In its classrooms, there are special boxes for storing students’ cellphones. “We have to hand in our cellphones every morning and get them back after school,” said Huang Jiameng, 15.

Astronauts go on spacewalks for many reasons. Spacewalks let astronauts work outside their spacecraft (飞行器) while still in space. Astronauts can do science experiments on a spacewalk. Spacewalks also let astronauts test new equipment (设备). They can repair spacecraft in space instead of bringing them back to the Earth to fix.

When astronauts go on spacewalks, they wear spacesuits with pure oxygen (纯氧) inside to keep themselves safe. Once in their suits, astronauts breathe oxygen for a few hours. Breathing only oxygen can help clear out all the nitrogen (氮气) in an astronaut’s body. If they didn’t clear out the nitrogen, the astronauts might get gas bubbles (气泡) in their body and the bubbles will do them harm. These gas bubbles can cause pain in astronauts’ shoulders and knees. This pain is called getting “the bends” because it has influences on the places where the body bends.

Astronauts are now ready to get out of their spacecraft. They leave the spacecraft through a special door called an airlock. The use of the airlock is to stop air getting out. The airlock has two doors. When astronauts get ready to go on a spacewalk, they go through the first door and lock it tight behind them. They can then open the second door without any air getting out of the spacecraft. After a spacewalk, astronauts go back inside through the airlock.

How do astronauts stay safe during spacewalks? They use safety ropes to keep themselves from floating away (飘离) into space. When on a spacewalk, one end of the safety rope is hooked (钩住) to the space walker while the other end is connected to the spacecraft. Astronauts also use ropes to keep tools from floating away. They tie their tools to their spacesuits.

Another way astronauts stay safe during spacewalks is by wearing a SAFER. If an astronaut were to float away, SAFER would help him or her fly back to the spacecraft. Astronauts control SAFER with a small joystick (控制杆), like on a video game.