How fit are your teeth? Are you lazy about brushing them? We brush our teeth every day but few people know how well we're brushing. Today, a French company has introduced an electric toothbrush, which can work wirelessly（无线地）with a smartphone. It's called the Kolibree toothbrush. It has different models, and will cost from$99 to$200 .The US is the first target market.

Users download an app and connect via Bluetooth, and the Kolibree will record: 1 .the time you spent brushing teeth. 2.whether all areas of your mouth are reached.

Do you know the numbers 0—9 well? They are numbers in Arabic numerals. People use them to mark numbers now. But it’s not the only number system that people use.

About 2, 500 years ago, people in Rome used their bands to count. In Roman numerals, two fingers means 2, three fingers means 3, you can keep your four fingers close on one side and your thumb on the other side. If you want to say five, you can keep your four fingers close on one side and your thumb on the other side. Make each of your hands be five, then you’ll have ten. So in Rome, the numbers are ‘I, Ⅱ, Ⅲ, IV, V, VI, VⅡ, VⅢ, IX, X’ ” Also, “L” means fifty, “D” means five hundred and “M” means one thousand. But there is no zero in Rome numerals. Today, few people use them because they are difficult to write and count. But we can still see them on some watches and clocks.

Today, most people use the Arabic numerals. They are easy to remember and write. They help people to count things every day. In fact, Indians first created and used the Arabic numerals. In the late 8th century, people in Arabic countries learned about them. Then the Arabic people took them into Europe. So people in Europe called them Arabic numerals. Today, people around the world use Arabic numerals and they help a lot.

AI (人工智能) makes our lives easier and better. Let’s see the amazing AI.

Cool driverless bus

A bus door opens and you get on. Wait! Where is the driver? Here is a new kind of driverless bus called Apolong. It has 14 seats and doesn’t need a driver. The bus follows traffic rules. It stops as soon as it sees a stop light.

Your close friend

Hi, everyone. I’m Xiaoice, a chatbot (聊天机器人). I speak like a 17-year-old girl. If you feel lonely, you can talk with me. I’m talented at singing, writing poems and telling stories. I want to be your friend!

World’s first AI anchor

Hey, look! The famous Chinese anchor(主播) Qiu Hao is reporting the news for us. But, is “he” really Qiu Hao? The answer is “no”. This is the world’s first AI anchor. It looks and speaks just like a real person. It can work 24 hours and doesn’t make any mistakes. You might see it on TV soon.

Popular AI artist

This beautiful painting was at an auction (拍卖) in 2018. It sold for 3, 000,000 yuan! But it is not a work by a famous painter, such as Vincent van Gogh. It was painted by an AI arts. Three Frenchmen created the AI.

The AI artist studied over 15, 000 paintings. In this way, it learned to paint. Now it is among the most popular artists in the world.