Agence France-Presse: A city in northern China notorious for its pollution and deadly mining accidents is having trouble finding willing candidates for mayor and Communist Party chief, state media reported Wednesday. The two top posts have been vacant since September in Linfen, regularly cited as one of China’s most polluted cities, when their former occupants were sacked over a mining disaster that killed 270 people, the China Daily said. The paper quoted political experts as saying the posts were …