单项选择题
Argon is classified as a（）.
A.corrosive B.flammable gas C.flammable liquid D.nonflammable gas
单项选择题 Another name for coal naphtha that would appear on a dangerous cargo manifest is（）.
单项选择题 All of our export dangerous goods are（）the standard.
单项选择题 All of our export dangerous cargo is（）examined before shipment.
