Alvin (middle), Simon (left) and Theodore of film "Alvin and the Chipmunks"   Chipmunks Alvin, Simon and Theodore, three well-loved animation characters, hit Chinese screens for the first time Monday (Feb. 8), with the live-action/ CGI comedy film "Alvin and the Chipmunks: The Squeakquel."   A sequel to the 2007 blockbuster Alvin and the Chipmunks, the film stars Jason Lee as David, with the voices of Justin Long, Matthew Gray Gubler and Jesse McCartney. In the sequel, the Chipmunks are sent back to school after reaching fame and