Flowers are seen in the park of the International Horticultural Exposition 2011 in Xi'an, capital of northwest China's Shaanxi Province, April 23, 2011. The International Horticultural Exposition 2011 will kick off here on April 28, 2011. (Xinhua/Jiao Weiping)

Photo taken on April 23, 2011 shows a horticultural artwork of the International Horticultural Exposition 2011 at the exposition park in Xi'an, capital of northwest China's Shaanxi Province. The International Horticultural Exposition 2011 will kick off here on April 28, 2011. (Xinhua/Jiao Weiping)

People stroll in the park of the International Horticultural Exposition 2011 in Xi'an, capital of northwest China's Shaanxi Province, April 23, 2011. The International Horticultural Exposition 2011 will kick off here on April 28, 2011. (Xinhua/Jiao Weiping)

People stroll in the park of the International Horticultural Exposition 2011 in Xi'an, capital of northwest China's Shaanxi Province, April 23, 2011. The International Horticultural Exposition 2011 will kick off here on April 28, 2011. (Xinhua/Jiao Weiping)

People take photos for "Chang'an Flower", the mascot statue of the International Horticultural Exposition 2011 in the exposition park in Xi'an, capital of northwest China's Shaanxi Province, April 23, 2011. The International Horticultural Exposition 2011 will kick off here on April 28, 2011. (Xinhua/Jiao Weiping)