-- Do you think the rain will stop tomorrow?         -

--        . It has rained for four days. It's too wet everywhere.

A．I hope not

B．I don't think so

C．Don't worry

D．I hope so

鉴别原料品质的理化指标是有毒物质、化学物质、酸碱度、硫化氢、胺、（）的含量。