As to his criticism, I don’t mind it in the least, but______is how he does it that I can’t take.

A．which

B．that

C．this

D．it

浊度测定时，水样中应无碎屑及易沉降的颗粒。如所用器皿不清洁或水中有溶解的（）和（）时干扰测定。