A.60%~70% B.80%~90% C.30%~40% D.50%
A.水垢 B.蒸汽 C.凝結(jié)水 D.雜質(zhì)
A.0.02~0.1 B.0.2~0.3 C.0.3~0.4 D.0.5~0.6