Dental decay, also known as dental caries, begins first inside the tooth. A white spot appears on the enamel where the tooth has started to weaken inside. At this stage, the tooth can repair the weakened area with the help of fluoride and minerals in saliva.
Beijing, also Peking, is the capital of the People's Republic of China and one of the most populous cities in the world. Its population in 2013 was 21,150,000. The city proper is the 3rd largest in the world.
A tallying of the figures for these ten groups produces a total population of slightly more than thirteen million (13,152,200) or about 1.3 percent of the total Chinese population. Beijing's general practice has been to avoid referring to these minority groups as Muslims per se, the rationale being that many members of the minority in question no longer believe in religion.