--- I’m sorry that I can’t go to your party tonight.

---- ______ ? Haven’t we agreed on it ?

A．What is it

B．Why don’t you

C．What do you think

D．How is it

取一杯浑浊的河水，为除去其中的泥沙（固体悬浮物），下列净水方法中最好采用（　　）

A．加絮凝剂

B．加活性炭吸附

C．过滤

D．蒸馏