During the 2022 Beijing Winter Olympic Games, there were 10 flower beds (花坛) . One of the high-lights (亮点) of these flower beds was to make good use of garden waste.

One of them was in Tian’anmen Square. Its topic was “Wonderful Winter Olympics”. The five Olympic rings and the snowflake shape were at the bottom of the flower bed. To our surprise, all of these were made from garden waste. This could not only save resources (资源)   but also bring people more beauty. It was generally praised by the public.

Green Olympics is one of the four main ideas of Beijing Winter Olympics. It took more than six years to prepare for the Games. In this process, the designers put the idea of green Olympics into every part. They integrated green Olympics with the city and its surroundings (环境) . Green Olympics can not only make good use of waste and protect the environment, but also be good for the future development of the city. There’s no denying that the Winter Olympics theme flower beds, which reflected the “simple, safe and wonderful” requirements for the competition, added points to the unique charm of the “City of the Two Olympics”.

As waste is considered as a resource that is put in a wrong place, the designers made the waste in the right place for the 2022 Beijing Winter Olympic Games. Besides, thrif (节俭) and hard work are the tradition of the Chinese nation. We also should save energy and make good use of waste in our daily life.

What is the most stressful thing in school? It is probably the exam. Exams can put us under a lot of pressure. But some students do well under pressure, while others feel terrible. So, why do some students perform better under stress?

It all comes down to dopamine (多巴胺). Dopamine is a chemical (化学物质) in our brain that sends signals (信号) to our body. It has many important roles: influencing memory, attention and how we learn. Our brains work best when there is a balance of dopamine — not too much or too little.

Our brains control dopamine in two ways. It either takes out dopamine quickly, or gradually. Exam success can be connected to how fast dopamine goes back to a balance, according to new research from the University of Missouri, reported Yahoo.

What happens when we take an exam? If you become stressed, your brain will start to overload on dopamine. It is like a cup overflowing with water. The quicker you can go back to a balance of dopamine, the quicker you will concentrate, helping you perform better in an exam.

Scientists found that，during a test，people who slowly got back to an even balance of dopamine scored 8 percent lower. That's the difference between a good mark and a bad mark.

But don't fear, there is some good news for every student. The study also found that the more practice you get, the less stressed you'll be.

So, it turns out that practice really does make perfect.