There is a small thing we use every day. We usually put ____1____ in the bathroom. Without it, we might have tooth problems. Can you guess ____2____ it is? Yes, it’s the toothbrush. But do you know anything about its history?

According to some research, before toothbrushes appeared, the ancient Chinese people ____3____ their teeth with some small tree branches (树枝). About 800 years ago, people made a kind of brushes with pig hair and bamboo. It might ____4____ the world’s earliest form of toothbrushes. As time went ____5____, the forms of toothbrushes changed. For example, people chose horse-tail hair instead of pig hair ____6____ pig hair was too hard. Imagine that you travel back to ____7____ of years ago and brush your teeth comfortably. It sounds fantastic, doesn’t it?

Around the 15th century, the Chinese toothbrush found its way into Europe. It became ____8____ among local people soon. The ____9____ of toothbrushes was not as famous as that of paper-making, but it was very useful in daily life. Today we have a good ____10____ of brushing teeth. We should thank the ancient Chinese for it.