

A visitor looks from outside the Danish pavilion at the Shanghai World Expo on April 25. The expo started trial operations on Tuesday with participation from about 70 percent of the pavillions, Xinhua reported. The Shanghai World Expo opens on May 1. Reuters
A laborer works on the exterior of the Shanghai Corporate Pavilion, known as the Dream Cub, at the Shanghai World Expo site on April 5. The World Expo is expected to run from May 1 to October 31 with about 70 million visitors attending.
Visitors line up to enter the French pavilion on April 23. Reuters
People visit the Spanish pavilion on April 23. Reuters
A worker stands in front of the Turkish pavilion at the Shanghai World Expo site on April 18. Reuters
A visitor stands at the South Korean pavilion on April 23. Eugene Hoshiko/AP
People photograph in front of of the Swiss pavilion on April 21. Aly Song/Reuters
A worker stands near the British pavilion on March 25 in Shanghai, China. Eugene Hoshiko/AP
Seeds are encased in acrylic poles used for the facade of the Seed Cathedral, the centerpiece of the UK's pavilion at the Shanghai World Expo site on March 15. The 60-foot-cube-like structure is covered by 60,000 slim, transparent acrylic rods. Aly Song/Reuters
A construction worker is seen at the Mexican pavilion at the Shanghai World Expo site on April 7. Aly Song/Reuters
Monaco's pavilion is seen at the World Expo, April 18. Reuters
People visit Iceland's pavilion at the World Expo on April 23. Reuters
The exterior of Finland's pavilion is prepared on March 17 in Shanghai. Reuters
Poland's pavilion is seen at the Shanghai World Expo on April 21. Aly Song/Reuters
A visitor walks past the Dutch pavilion on April 21. Aly Song/Reuters
The Japanese pavilion is seen at the World Expo on April 23. Eugene Hoshiko/AP
The United Arab Emirates' pavilion is seen at the Shanghai World Expo on March 2. Aly Song/Reuters
Workers are seen at Luxembourg's pavilion on March 2. Aly Song/Reuters
On April 21, visitors walk past Portugal's pavilion in Shanghai. Aly Song/Reuters
Work takes place on the Slovenian pavilion on April 21. Aly Song/Reuters
North Korea's pavilion at the Shanghai World Expo is seen here on April 15. Reuters
The Belarussian pavilion is seen on April 21. Aly Song/Reuters
A general view of the Caribbean Community pavilion is seen on April 18. Reuters
A worker arranges the exterior of the Brazilian pavilion on April 23. Eugene Hoshiko/AP
Laborers work on India's pavilion on April 13 in Shanghai, China. Reuters
Germany's pavilion is seen on April 21 at the Shanghai World Expo site. Aly Song/Reuters
Visitors walk around the Shanghai World Expo site during a trial opening day in Shanghai on April 20. AP
On April 21, the Greek pavilion is seen in Shanghai, China. Aly Song/Reuters
Sweden's pavilion is seen on April 21. Aly Song/Reuters
Hungary's pavilion is seen on April 23 at the Shanghai World Expo site. Reuters