When you meet a strange Chinese character (汉字) what will you do? Surely, the most reliable way is to look it up in Xinhua Dictionary.

Since its birth in 1953, Xinhua Dictionary has been a must-have book in schools across China. More than 567 million copies had been sold by 2016. So it was even recognized by the Guinness World Records as the “most popular dictionary” that year.

Small as the dictionary is, it means a lot to China. The dictionary was given the name Xinhua by the chief editor Wei Jiangong, and it carried the hope of a country reborn. In 1949, around 80% of China’s population wasn’t able to get education (教育). It was Xinhua Dictionary that had reduced the number to 52% by 1964. To make it easier for illiterate people to understand, the earliest copies had many pictures.

Thanks to Xinhua Dictionary, many Chinese got new chances in their life. Mo Yan, the 69-year-old Nobel Laureate, once mentioned the dictionary in his speech. He said that he was lucky to have a copy of the dictionary after dropping out from school. He learned most of Chinese characters from it, and that helped him write novels and enter a college later.

This important dictionary has also recorded the development of the language and society. It is revised (修订) every five to ten years. Recent copies have included many new explanations. The character “晒” (to dry something in the sun), for example, now has a second meaning: to share. In a way, the dictionary hasn’t just explained characters; it has reflected (反映) the way Chinese people think.

In a noisy restaurant, you can still hear your friend’s voice clearly. You talk happily without paying attention to others’ conversations. That’s because selective (选择性的) attention is helping you.

Selective attention is an amazing ability in our brain. It allows people to choose and focus on (专注于) something in the environment. At the same time, it can filter out (过滤) unnecessary information, so people can focus on one conversation in a crowded place. But how does selective attention work? Researchers from Columbia University did an experiment to study it. The result shows that the brain is selective about the sounds it hears. When a person listens to someone talking, their brain waves (波) change to pick out the features of the speaker’s voice and filter out other voices.

To further understand how selective attention works, the researchers studied two parts of the brain’s listening centre: Heschl’s gyrus (HG) and the superior temporal gyrus (STG). Information from the ears reaches HG first, passes through it and arrives at STG later. In the study, they found the following facts: in HG area, every voice is treated the same way. That is to say, HG doesn’t prefer one voice or another. But in STG area, it’s possible to choose one speaker’s voice and make it louder. The whole process (过程) only takes 150 milliseconds and it happens immediately to a listener. As a result, people can focus on one voice when there are many other conversations around.

“Today’s study is quite important. We want to better understand how the brain helps us to hear so well, as well as create technologies that help people,” said Dr. Mesgarani, the leader of the researchers. With the help of the finding, speech recognition technologies have been improved. The researchers have already developed a new kind of hearing aid that can help collect information more correctly. It could make one speaker’s voice louder over another. They also plan to study more about HG and STG activity in situations that have more speakers.

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7 . Solving climate change may bring unexpected benefits. There is a special exhibition - Our Future Planet in London Science Museum. It is about carbon capture (碳捕集), the new technology of getting greenhouse gases (温室气体) from the atmosphere and emissions from factories.

The exhibition shows bottles, tubes, pens and yoga mats made from carbon as well as models of the carbon capture machines that can provide this carbon. They include the Lackner artificial tree which mirrors the actions of living plants by breathing in carbon dioxide (二氧化碳) and exhaling oxygen (呼出氧气). It was built by Klaus Lackner. The device is amazing, but its structure is complicated and the usage is limited (限制的). Besides, there also are the Swiss Climework’s carbon extractor system and a carbon capture device developed at Aberdeen University. All can remove carbon from air to be used for alcohol or other products.

To help protect the planet from the effects of Global Warming, we have to do more than only stop carbon dioxide getting into the atmosphere. We also need to find ways to remove carbon dioxide after it has been put there. Simply planting trees and plants will not be enough to solve the problem. Firstly, the machine can be fitted to gas and coal- burning power stations and factories and then used to hold back the carbon dioxide they would emit (排放). The technology can also be used to recapture carbon dioxide that had already been in the air.

But the exhibition also makes it clear that even moderately large groups of these devices now can remove only a few tens of tonnes of carbon a year- compared with the 50 billion tonnes that cars and factories add to the atmosphere every year. So, it’s urgent (紧急的) to develop and use these new technologies on a large scale (规模) to make a real difference in fighting climate change. Using these on a large scale will be very hard.

However, there is still a hopeful route. It is like the mobile phone. Twenty years ago, they were expensive and difficult to use but have been improved upon relentlessly (不停地). These gas- harvesting machines can be improved upon quickly by generations, so that they will be cheaper and more efficient in the future. If we don’t do something like that we will be in real trouble.

Big moments of the past 25 years

Hong Kong came back to China 25 years ago. There were many important moments.

1997

Hong Kong was returned to China. The “one country, two systems” policy started.

2003

Individual visits began. Before that, people from the mainland could only visit Hong Kong in groups.

2005

Hong Kong Disneyland opened in September. It is China’s first Disney theme park.

The city held the equestrian sports as part of Beijing Summer Olympics.

2012

Hong Kong high school graduates could study at some universities on the mainland. They just need to offer their local grades.

2018

Hong Kong-Zhuhai-Macao Bridge opened in October. People can drive from Hong Kong to Zhuhai in just 45 minutes.

2022

The government decided to improve Hong Kong International Airport. It will welcome 0.2 billion visitors every year in the future.

10 . Mobile apps are great and they can do so much to improve our lives. Here, we picked out three of our favourites that we hope you will enjoy too.