A.50ppm B.80ppm C.100ppm C.150ppm
A.1/2-1/3 B.1/3-1/4 D.1/5-1/6 C.1/9-1/10
A.燒結(jié)礦帶 B.燃料帶 C.干燥預(yù)熱帶 D.水分冷凝帶