测定天然水的色度通常采用铂钴比色法，色度单位的规定为（）

A.1mg铂所具有的颜色称为1度

B.2mg铂所具有的颜色称为1度

C.2mg/L铂所具有的颜色称为1度

D.1mg/L铂所具有的颜色称为1度

E.5mg/L铂所具有的颜色称为1度

A．Most victims were rescued successfully.

B．Someone in the firm was to blame for the explosion.

C．The firemen were very brave.

D．The press reporter arrived too late to interview anyone.