单项选择题
The fire of burning plastics is classified as （） fire.
A.Class A B.Class B C.Class C D.Class D
单项选择题 The pistons are cooled by （） oil from the forced lubrication.
单项选择题 Engine parameters shall be corresponded to NOx Technical Files,This is required by（）
单项选择题 Ships do not permitted to the TBT paint after 2008，It is required by（）
