单项选择题
A.anaerobic bacteria B.aerobic bacteria C.air bubbles D.disinfection chemicals
The extended aeration process consists of （） the liquor...
单项选择题The extended aeration process consists of （） the liquor either by bubbling air through it or by agitating the surface.
A number of biological sewage treatments plants are in ...
单项选择题A number of biological sewage treatments plants are in use at sea but nearly all work on the principle called （）
A.deoxygenating B.extended aeration C.oxygenating D.bubbling air
Which of the following would not be burnt in an inciner...
单项选择题Which of the following would not be burnt in an incinerator on board?（）
A.waste oil B.waste cloths C.Oil rags D.Waste food
