Backgrounder: History of China's presence at World Expo

MILAN -- As a top-level global exhibition dated back to the Great Exhibition of London in 1851, the World Expo has been serving as a grand bridge for economic, technological, social and cultural exchanges, and cooperation among participating countries.

There are two types of world expositions: the Registered International Exhibitions (formerly called Universal International Expositions) and the Recognized International Exhibitions (formerly called International or Specialized International Expositions), according to the Bureau International des Expositions, an intergovernmental organization created to regulate the World Expo.

The Registered International Exhibitions may occur every five years since 2000, lasting six months, for example, the Expo 2010 in Shanghai and the Expo 2015 in Milan.

The Recognized International Exhibitions may occur between the Registered International Exhibitions and last for three months in general, for example, the Expo 2008 in Zaragoza, Spain, and the Expo 2012 in Yeosu, South Korea.

Since 1982, under the authorization of the Chinese government, the China Council for the Promotion of International Trade has organized the China Pavilion for 15 world expos, including the following:

-- Expo Knoxville 1982, the United States, themed "Energy Turns the World"

-- Expo New Orleans 1984, the United States, themed "The Worlds of Rivers-Fresh Water as a Source of Life"

-- Expo Tsukuba 1985, Japan, themed "Living and Environment Household Science and Technology for Human Beings"

-- Expo Vancouver 1986, Canada, themed "World in Motion-Would in Touch"

-- Expo Brisbane 1988, Australia, themed "Leisure in the Age of Technology"

-- Expo Seville 1992, Spain, themed "Age of Discovery"

-- Expo Genoa 1992, Italy, themed "Christopher Columbus -- the Ship and the Sea"

-- Expo Taehung 1993, South Korea, themed "A New Path Forward"

-- Expo Lisbon 1998, Portugal, themed "Oceans -- A Heritage for the Future"

-- Expo Hannover 2000, Germany, themed "Humankind, Nature, Technology and Development"

-- Expo Aichi 2005, Japan, themed "Nature's Wisdom"

-- Expo 2008 Zaragoza, Spain, themed "Water and Sustainable Development"

-- Expo Shanghai 2010, China, themed "Better City, Better Life"

The Expo Shanghai 2010, the first Universal International Exposition held in China and with 246 nations and international organizations participating, embraced 73.08 million visitors, a record high in the World Expo history.

China is presenting a self-built and the second largest foreign pavilion at the ongoing Expo Milan 2015 themed "Feeding the Planet, Energy for Life".