Garbage sorting is a big issue worldwide. In recent years, some Chinese cities have been working hard on it.

Shanghai has worked with Alipay to create a “green account (账户)” service for its residents (居民). Account holders get points by correctly sorting their garbage. Through the Alipay app, they can exchange the points for milk, phone cards and other products. The city is asking all of its residents to sort their garbage into four groups: wet, recyclable, harmful and dry.

Wet waste is also known as household waste. “They are things you don’t want but that pigs can eat,” Guangzhou Daily explained. Paper, metal (金属), glass and other things that can be reused are recyclable waste. Harmful waste includes things like medicine, batteries and fluorescent bulbs (荧光灯泡). Finally, any waste that’s not wet, recyclable or harmful will go in the “dry waste” bin.

Many other Chinese cities are also using this method to sort their garbage. For example, Shenzhen has been sorting its garbage into the same four groups since 2012. Students there also receive waste-sorting guidebooks that they must study.

China is improving its waste-sorting efforts. There is still a long way to go. But it’s never too late to learn how to sort your trash properly and protect the environment.

If you don’t sort your garbage, all of it will go to a landfill (垃圾填埋场) and be buried together. These landfills can take up large areas of ground that could have been used for planting trees or crops. The electronic waste you throw away, such as batteries, can pollute the soil and groundwater. Other pieces of garbage, like the metal part of a pen, can be used to make other things if they are properly recycled.

Actually, a plane’s black box is bright orange. It is easier for people to find the box after a crash (坠机).

The boxes are made of very strong materials. It gives protection from the crash itself. And it protects against very high heat and fire.

Many people are surprised to learn that black boxes are not found up front in the cockpit. Instead, they are placed in the plane’s tail.

A black box is a powerful data (数据) collection device. We also call it plane’s flight data recorder (FDR).

Black boxes record important information. The information helps people understand and explain what went wrong. As a result, plane designers can make changes so the problem will not happen again.

When your alarm clock rings and you drag yourself out of bed, you probably wonder: Why on Earth does school have to start so early?

Fortunately, there is a new law to back you up or better still, science. A law in California, passed on Oct 13, requires that public middle schools begin classes no earlier than 8:00 am and high schools start no earlier than 8:30 am. The law will go into effect by July 1, 2022.

Starting school at 8:00 or 8:30 in the morning may not sound like too big of a change, but it could mean one more hour of sleep for students who used to start school at 7:30 or even earlier.

“The effect of that one hour is something they will be feeling as 40-year-old adults,” Sumit Bhargava, a sleep expert at Stanford University, told The New York Times. He said that not having enough sleep can affect students’ mental health and increase the risk of obesity and diabetes (糖尿病).

In the short run, students’ school performances should improve almost immediately. Kyla Wahlstrom, a researcher at the University of Minnesota’s College of Education, found that students who have enough sleep are more quick﹣minded in class and get better grades.

Some might say that getting students to go to bed earlier could have been a much easier solution than changing the school timetable across an entire state. But according to the American Academy of Sleep Medicine, teenagers go through biological changes when they enter puberty (aged from ten to nineteen), which makes it difficult for them to fall asleep before 11:00 pm. So when school starts at 8:00 or earlier, they can hardly get the ideal 8.5-9.5 hours of sleep that experts suggest they need to do their best in the daytime.

This is why when the new law came out, its author, Anthony Portantino, said, “Generations of children will come to appreciate this historic day and our governor for taking bold (brave) action.”