In Chinese, we say “mai dongxi” to mean “buy things”. But why is it “dongxi” and not “nanbei”? “Dong” and “xi” are directions. How can we “buy” them?

Many people believe “mai dongxi” has something to do with a city in ancient China. It was called Chang’an. Today, we call it Xi’an. Chang’an was the capital of many Chinese dynasties (朝代), such as the Tang Dynasty. There was a long road that cut the city in two—the eastern part and the western part. There was a big market in each part.

The two markets sold different things. The western market drew many businessmen, workers and foreigners. Common people could buy food and daily goods there. They could also find things from foreign countries, such as Rome. However, the eastern market sold more expensive things, so more officials (官员) and nobles (贵族) went there.

People often said “buy east” if they were going to the eastern market to buy goods. And they said “buy west” when going to the western market. As time passed, “dongxi” became the word for “goods” and “things”.

Do you find it hard to remember words? You may not be the only one. Now a new study says that you can draw a picture of something to remember it better.

Some Canadian scientists did the study. They first gave a group of students a few words such as “apple” and “water”. Then they gave the students 40 seconds to memorize them. The students could write the words again and again. They could also draw a picture of the words.

When the time was over, the scientists asked the students to sing a song. After that, they gave the students 60 seconds. The students had to write down as many words as they could remember. Guess what? Those who drew the words did a much better job than those who wrote them.

And don’t worry if you are not good at drawing. The scientists say the quality(质量) of the drawing doesn’t matter(紧) at all .

Take a look at the trash bins (垃圾桶) outside your house. They often come in different colors. But this isn’t just for fun—those colors tell you how you should sort (分类) your trash.

Not all trash is the same. There is household trash (厨余垃圾) —things like banana peels. There’s harmful trash, such as medicines. And then there’s recyclable trash, like bottles. It’s important to sort these kinds of trash correctly.

Sorting trash can help us in many ways. We can make sure that harmful things, such as medicines, don’t pollute our ground and water. We can re-use some trash, such as paper, glass and old clothes, to make new things. Countries around the world have found many different ways to take care of their trash. For example, in the UK, there are now “smart” trash bins. These bins can sort trash by themselves. People just need to drop their trash into the bin and it will take care of the rest. Do you know where your trash goes after you throw it away? Most trash goes to landfills (垃圾填埋场) . They are usually far away from where people live. Recycled trash goes to recycling centers. These centers use the trash to make new things. Finally, some trash goes to “waste—to—energy” factories. These factories burn the trash and turn it into energy. To sort the trash is to protect your homeland.