Warning marks are obvious symbols or words to warn people against the hidden of inflammables, explosives and poisonous products, e.g. “CORROSIVES”, “EXPLOSIVES”, “POISON”, “INFLAMMABLE”, “ACID WITH CARE”, etc.

Warning marks are obvious symbols or words to warn people against the hidden of inflammables, explosives and poisonous products, e.g. “CORROSIVES”, “EXPLOSIVES”, “POISON”, “INFLAMMABLE”, “ACID WITH CARE”, etc.
A.satisfactory
B.strong
C.damage
D.danger
正确答案：D