Do you know why different animals or pests have their special colours? Colours in them seem to be used mainly to protect themselves. Some birds love eating locusts (蝗虫), but birds cannot easily catch them, why? It is because locusts change their colours with the change of the colours of crops. When crops are green, locusts look green. But as the harvest (收获) time comes, locusts change to the same brown colour as crops have. Some other pests with different colours from plants are easily found and eaten by others. So they have to hide themselves for living and appear only at night.

    If you study animals' life, you'll find the main use of colour is to protect themselves. Bears, lions and other animals move quietly through the forests and they cannot be easily seen by hunters. This is because they have the colours much like the trees.

    Have you ever noticed an even stranger act? A kind of fish in the sea can send out a kind of very black liquid (液体) when it faces danger. While the liquid spreads, its enemies cannot find it. And it immediately swims away. So it has lived up to now though it is not strong at all.

    As is known to all of us, Beijing Opera is one of the most important opera styles in China. It is an art on the stage which has about 200 years' history. It is not only a treasure of the Chinese nation but also a cultural symbol of China. Similar to western operas, Beijing Opera is a combination of singing, dancing, martial arts, music and literature, so it is also called the "Oriental (东方的) Opera" by western people.

    Beijing Opera uses special imagery in creating the characters. All roles are divided according to sex, personality, age and profession and social status. Hangdang is the general term for role in Beijing Opera. There are four types of roles in Beijing Opera today. They are sheng, dan, jing and chou. The sheng is the male protagonist (主角), the dan the female protagonist, the jing (painted face) a male supporting role with a different characteristics, and chou (clown) a comic or negative figure. Each kind of role has their own face-painting and dressing to indicate their identities.

    The Opera's performance requires not only the gentle voice but also the proficiency (熟练) of martial actions. A successful opera actor must suffer from the tough practicing period. In the old time, the children of poor families were sent to the opera group in order to earn a living. While now, the real opera artists are well respected by opera lovers.

    Mei Lanfang, one of the most remarkable performing artists in Beijing Opera, was born in Beijing into a poor family. His life was bitter and he had no opportunity to go to school, so he went to the troupe (戏班子) when he was 8 years old to learn Beijing Opera. Mr. Mei was on the stage when he was 11 years old to perform the plays of Beijing Opera. He has been an opera actor for more than 50 years, performing hundreds of traditional plays and over 30 modern plays. He portrayed many bright and lifelike female figures on the stage and became the model in Chinese Beijing Opera and even within the entire artistic circle.

    English playwright Arthur Wing Pinero said, "Where there's tea, there's hope." Similarly, a Chinese saying goes that "Firewood, rice, cooking oil, salt, sauce, vinegar and tea are the seven necessities to begin a day."

    Tea is, without doubt, welcomed all over the world. According to Statista, a German website for statistics (数据), global tea production reached about 5.8 million tons in 2018. It has become the most consumed beverage (饮品) in the world – after water, of course.

    According to the UN, tea is much more than just a hot drink. It's a big part of many cultures around the world. You probably know that people in China use top-grade tea to show respect when receiving important guests. Meanwhile, the British tradition of afternoon tea is an important part of that country's identity. Making Malaysia's pulled tea has become a sort of art form, where drinkers take pride in its entertainment aspects.

    Apart from its cultural significance (意义), tea is also a medicine, used from ancient times to modern day. "Tea is cold and lowers the fire," Chinese Ming Dynasty herbalist Li Shizhen once said. The health benefits of tea are still being discovered today: preventing heart disease, obesity and cancer have all been linked to drinking green tea, according to the National Center for Biotechnology Information in the US.

    Hot or cold, bagged or loose-leaf, tea is more than a drink – it's a social custom and also a magic medicine, a link to the past and a way of life.

Doorbells are the bells (铃) for people to ring at a door. When someone hears it, he or she can open the door. Do you know that you can ring a doorbell for fish, too? 

Every spring, millions of fish migrate (洄游) along the river in the city to find better places to lay eggs. But in the river, there are many locks (水闸). They stop fish from swimming through. Weerd Lock is in Utrecht, the fourth largest city in the Netherlands (荷兰). When fish get there, they have to wait a long time before the lock opens for boats to pass through. The lock keeper there is glad to open the lock for fish, but he cannot tell when fish want to get through. So in 2021, Mark van Heukelum, a scientist, came up with a good idea to help solve this problem—by using the fish doorbell. 

Under the water near the lock, there's a camera. People from around the world can visit a website (网站) to see fish through the camera. When you see a group of fish waiting, you can ring the doorbell on the screen. And when the lock keeper notices it, he will open the lock for the fish. 

In its first spring season in 2021, people around the world rang the fish doorbell more than 100,000 times. If you want to join them to help fish, visit the website and ring the fish doorbell next spring. 

How to learn English

How can you learn English well? Here are my suggestions. 

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I hope these suggestions can help you.