生物 せいぶつ化学 かがく てき酸素 さんそ要求 ようきゅう りょうであれば
seibutsuka gakuteki sansoyō kyūryōdeareba

Noun
Da Copula

The "-eba" conditional form ("if/when…") of 生物化学的酸素要求量

1. If it were biochemical oxygen demand; Were it biochemical oxygen demand

Ba Conditional