不属于钢材表面处理方法的是（）。

A.手工方法

B.机械方法

C.物理方法

D.化学方法

Passage Three

What did the Norwegian Foreign Ministry do in response to this kidnapping

A．They prepared the ransom demanded by the kidnappers so as to rescue the victims.

B．They demanded that the local Nigerian authority should be held accountable to this incident.

C．They conducted investigation so as to collect more information concerning the kidnapping.

D．They sent negotiators to talk the kidnappers into releasing the hostages.