A.齿轮啮合不正常 B.溜槽里煤量过多 C.刮链板过松 D.连接螺栓松动或脱落
A.30 B.20 C.10 D.5
A.肝炎 B.糖尿病 C.高血压 D.痛风
A.10 B.30 C.15 D.20
A.20%~30% B.25%~30% C.30%~40% D.35%~40%