A. 20%~25%:25%~30%:50%~60% B. 10%~15%:20%~35%:50%~60% C. 10%~25%:25%~30%:50%~60% D. 10%~15%:25%~40%:50%~60% E. 15%~25%:30%~45%:45%~60%
A. 瘦煤 B. 肥煤 C. 焦煤 D. 烟煤