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.
5. Beijing, which means Northern Capital (from the Chinese characters å for north and äº¬ for capital), is the capital of the Peopleâs Republic of China and one of the most heavily populated cities in the world.eography. The metropolis is located in northern China and the municipality of Beijing extends over a surface of 16 800 km2. Mountains to the north, northwest and west shield the city which is close to the Great Wall of China.