The japanese conquest of burma cut china ' s last transportation route to the outside world ( from kunming to lashio via the burma road , and then by railroad to rangoon ) at the end of april , 1942 1942年4月底,日军占领缅甸,切断了中国与外界最后一条运输路线(从昆明经过缅甸公路到腊戍,然后走铁路到仰光) 。