

A worker adjusts a lighting installation inside the Chinese pavilion at the Shanghai World Expo site in Shanghai, China, on March 25. The World Expo will run from May 1 to Oct. 31 with 70 million visitors expected to attend. China Daily/Reuters
Singapore's pavilion is seen on April 23. Reuters
Turkmenistan's pavilion is lit up on April 27 at the World Expo site. Reuters
A night view of the Australian pavilion is seen here on April 23. Reuters
In July 2009, visitors are reflected in mirrors creating a sphere at China's pavilion, ahead of the Shanghai World Expo. Andy Wong/AP/FILE
A performer looks at the 'Energy Source,' a 1.2 ton sphere with 400,000 LED lights that reacts to sound at the German pavilion on March 30. Ng Han Guan/AP
Serbia's pavilion is seen at night at the Shanghai World Expo site on April 23. Reuters
A construction worker walks past an illuminated building at the Chinese Information and Communication Pavilion on April 19. Eugene Hoshiko/AP
The Brazilian pavilion is lit up on April 23. Reuters
An aerial view of the illuminated Shanghai World Expo site is seen on April 14. Shanghai Pacific Institue for International Strategy/AP
Poland's pavilion is pictured on April 23. Reuters
Japan's pavilion at the World Expo 2010 is seen illuminated on April 27. Reuters
Fireworks explode over China's pavilion on April 27 during a rehearsal for the opening ceremony of the World Expo 2010. Aly Song/Reuters
The Chinese pavilion is seen lit up during lighting testing at the Shanghai World Expo site on Dec. 30, 2009. Reuters/FILE
Canada's pavilion is lit up on April 27. Reuters
A night view of the Russian pavilion is seen here on April 23. Reuters
South Korea's pavilion is seen at night on April 27. Reuters
On April 23, the Spanish pavilion is seen illuminated at the World Expo site. Reuters
France's pavilion is seen lit up on April 22. Reuters
Norway's pavilion is illuminated on April 27. Reuters
On April 27, the Swedish pavilion is seen at night at the World Expo site. Reuters
Pakistan's pavilion is seen at night on April 27. Reuters
Laborers work inside the Brazilian pavilion on April 13. Reuters
A cone-shaped 'Sun Valley' is lit up at the 2010 World Expo site on April 25. China Daily/Reuters
A night view of the Turkish pavilion is seen on April 27. Reuters
Denmark's pavilion is pictured here on April 23 at the Shanghai World Expo 2010 site. Reuters