单项选择题
A.the bacteria
B.oxygen
C.oxidizing function
D.agitation function
单项选择题 The basic process of biological sewage treatment consists of the liquor either by bubbling air through it or by agitating the surface()
单项选择题 When the garbage is mixed with some discharges having different disposal or discharge requirements, shall apply()
单项选择题 Disposal of all kinds of garbage but is prohibited within Special Areas()