SHANGHAI -- Two hundred mentally challenged Chinese children visited the Shanghai World Expo Thursday.

They were mainly from Shanghai Minhang District Qizhi School for mentally impaired children and two schools for migrant workers' children: Shanghai Minhang District Wenhui School and Shanghai Minhang District Wenxin School.

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Deng Xiaodong, spokesperson for the Expo's volunteer department, said the program was part of a volunteer project to provide more care for disadvantaged groups including the disabled, children of migrant workers and those from relatively backward areas.

"I'm happy to be here. The Expo Park is so large. I don't want to leave. I have fun here." said 18-year-old Wu Bin, a student from Qizhi School.

Chen Huiling, an 11-year-old student from Wenhui Primary School, was invited to the Expo with her father Zhang Jinsong -- a construction worker who helped in the building of Expo Park.

"I came from Sichuan Province and have been living in Shanghai for four years," Chen said. Her father kept telling her where he had worked. "I am proud for my father," she said.

The children mainly visited the USA Pavilion, the Pacific Pavilion and the South Africa Pavilion. The project was initiated by the Chinese Communist Youth League Shanghai Municipal Committee and sponsored by Johnson & Johnson.