A.4% B.6% C.8%
A.68.03% B.78.03% C.88.03%
A.700~800 B.800~900 C.900~1000
A.反吹時(shí)間 B.清灰時(shí)間 C.反吹周期
A.為零 B.很高 C.很低 D.無(wú)影響