Food waste (食物残渣) is a big problem in Japan and the world. In 2019, Japan produced 5.7 million tons of food waste. The government is working on reducing this to 2.7 million by 2030.

Now, University of Tokyo researchers in Japan have created a new technology that uses food waste in a surprising way. Student Kota Machida and Professor Yuya Sakai say the operation can turn food waste into a strong material like cement (水泥). They say it is four times stronger than regular concrete and is sustainable. And you can eat it.

Through a process of drying, crushing, and compressing (压缩) the food waste, Sakai and his student Machida had successfully made cement from food waste without plastic. “The most challenging part was that each type of food waste requires different temperatures and pressure levels,” Sakai said.

The team have used different types of food waste to make the cement, including tea leaves, orange peels, coffee grounds, and leftover lunch materials. They’ve adjusted flavors with different spices and found the colors, smell and taste of the cement can be quite attractive.

Machida and his two friends have created a company called Fabula, Inc. They are working with other companies to use the material to make products for the home. “If this cement could replace plastic and cement products, it may help slow global warming linked to food waste,” said Machida.

【推荐2】Rivers are the lifeblood of human civilizations. As one of the longest-lasting civilizations, China has a large number of rivers. A total of 45,203 rivers with a drainage area (流域面积) of more than 50 square kilometers run across the country, according to the National Bureau of Statistics.

The most famous ones are the Yangtze and Yellow Rivers. As the longest river in Asia and third longest in the world, the Yangtze River has a length of 6,300 kilometers. It originates from the Qinghai-Tibet Plateau (高原) and flows through 11 provincial-level administrative regions (省级行政区) before ending in the East China Sea. Second to the Yangtze River is the Yellow River, with a length of 5,464 kilometers as it flows from the west to the east of China.

Apart from its big number of natural rivers, China also has a lot of beautiful man-made rivers. The Grand Canal is one example. With a history of more than 2,500 years, the Grand Canal stretches (延伸) nearly 3,200 kilometers and connects the north and south of China.

Despite their different features, these rivers and canals continue to nourish (滋养) the Chinese people physically and culturally. They bring fertile (肥沃的) soil and enough irrigation (灌溉) water, which makes many areas “a land of fish and rice”. Connecting China as a whole, the water network runs through geographical boundaries (界限) and provides people with convenient transportation, expanding trade and promoting economic growth. These rivers are immortalized (使名垂千古) in Chinese culture, as can be found in Chinese poetry, art, literature, and folklore.

Just as Chinese President Xi Jinping said, “Lucid waters and lush mountains are invaluable assets (绿水青山就是金山银山).”

To protect these bodies of water, many measures have been taken in recent years. For example, in August the Ministry of Water Resources announced plans to bring back 700,000 hectares (公顷) of degraded natural forest and treat almost 1.4 million hectares of land suffering from desertification (沙漠化) by 2025.

Through these government measures, our rivers have seen many positive changes—birds flying above the wetlands and farmers happily harvesting on irrigated lands.

Earthquakes show how powerful nature is and how they influence human’s lives in many ways. In an earthquake, the ground moves or shakes, sometimes very strongly. It can bring buildings falling down to the ground and break up roads, railways, and bridges. A big quake can also kill hundreds of thousands of people. That’s why it’s important to use special designs and technologies to make our towns safer from earthquakes when planning and building them.

These days, there are many ways for scientists to know an earthquake may be on the way. A seismograph is an instrument that picks up movement of the ground. Modern seismographs use computers that carry out results from the recordings right away. Scientists also use information from satellites which tell them when the ground is moving and an earthquake may happen soon.

But how do earthquakes happen? The earth has four main layers (层). The top of it is made up of many pieces. These pieces are called plates. The lines where plates meet are called faults. Three kinds of faults are created as plates move in different ways.

Usually, the plates move smoothly. But when they suddenly move several centimeters, pressure builds up where they are pushing into or against each other, so that earthquakes happen. Almost all earthquakes happen at faults. Most of the earthquakes happen along the coast. However, some happen in the middle of land, where the plates meet.

Overall, earthquakes teach us to respect nature’s power and get ready for surprises from it. They make us rethink the importance of understanding how our planet works and how we should live with it.