Fatality rate of pneumoconiosis patients in this group was 74.4%,and the average exposure time in pneumoconiosis patients was 17 years,the average morbidity age was 50 years.是什么意思_Fatality rate of pneumoconiosis patients in this group was 74.4%,and the average exposure time in pneumoconiosis patients was 17 years,the average morbidity age was 50 years.在线翻译_英语_读音_用法_例句