The Golden Gate Bridge is illuminated during its 75th anniversary celebration, San Francisco, the United States, May 27, 2012. Tens of thousand of people came to mark the 75th anniversary of the Golden Gate Bridge, which was opened in 1937. (Xinhua/Liu Yilin)

　　Celebration banners are seen near the Golden Gate Bridge during its 75th anniversary celebration, San Francisco, the United States, May 27, 2012. Tens of thousand of people came to mark the 75th anniversary of the Golden Gate Bridge, which was opened in 1937. (Xinhua/Liu Yilin)

　　The Golden Gate Bridge is illuminated during its 75th anniversary celebration, San Francisco, the United States, May 27, 2012. Tens of thousand of people came to mark the 75th anniversary of the Golden Gate Bridge, which was opened in 1937. (Xinhua/Liu Yilin)