Visitors walk inside a tunnel at the Science and Technology Museum in Tianjin municipality, May 19, 2012. State Councilor, Liu Yandong on Saturday opened China's annual "Science and Technology Week" by calling for accelerated scientific progress and the development of new technology, popularization of scientific knowledge and the creation of an environment for innovation. "Science and Technology Week" has been held annually since 2001 and more than 600 million people have participated in its activities. Various activities were organized in parks, schools or museums across the nation to improve the awareness of science and technology. [Photo/Xinhua] 

A boy brushes a teeth model at the Science and Technology Museum in the Tianjin municipality, May 19, 2012. [Photo/Xinhua]