—Does coffee really work when you have to work late into night?

—Yes. As far as I'm concerned, I feel very __________ after a coffee.[ ]

A. energetic  

B. normal

C. adequate  

D. sensitive

以下属于三级处理方法的是（）

A.生物脱氮除磷法

B.生物膜法

C.筛滤法

D.活性污泥法