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.
