A.計(jì)算B.經(jīng)濟(jì)比較C.試驗(yàn)D.經(jīng)驗(yàn)
A.接觸 B.曝氣 C.自然 D.藥劑
A.1.0%~1.5% B.1.5%~2.0% C.0.20%~0.28% D.0.6%~0.8%