Brush your teeth every day, dentists say. In the south of Africa, some people brush their teeth all day long. They keep a small stick in their mouth to chew or scrub   their teeth all day. People cut the sticks from trees. They are the African toothbrushes. People there are used to brushing their teeth with sticks. Africans think the sticks work better than toothbrushes. The sticks come from nature, and it is said that there is something special about them. The special thing may stop many kinds of tooth problems. "If you have a bad tooth, it is a medicine," said Diop, a seller in Africa. The sticks are also much cheaper than toothbrushes. In Senegal  ,the chewing stick is called "sothio". It means "to clean" in their language. In east Africa,the stick is called "mswaki". It's their word for "toothbrush". Even the dentists agree that the sticks seem to clean teeth better. Nowadays, some nice health stores in the United States start to sell chewing sticks. They think that the stick is natural kind of tooth care. Who brushes teeth with sticks first according to the passage?
The Africans. The Americans. The Chinese. The dentists.