There is a small thing we use every day. We usually put ____1__ in the bathroom. If we don’t use it, we might have tooth problems. Can you guess what it is? Yes, it’s the toothbrush. But do you know ____2___ about its history?

Before toothbrushes appeared, the ancient Chinese people ____3___ their teeth with some small tree branches (树枝). About 800 years ago, people ____4____ a kind of toothbrushes with pig hair and bamboo. It might be the world’s earliest form of toothbrushes. As time went by, the form of toothbrushes ____5___. For example, people didn’t use pig hair to make toothbrushes ____6___ it was too hard (硬的). They began to use horse-tail hair which was much softer. Imagine that you travel back to hundreds of years ago and brush your teeth ____7___. 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 get into the good ____10____ of brushing teeth. We should thank the ancient Chinese for it.