单项选择题
A.Toxic fumes of oxides of nitrogen
B.Toxic fumes of lead
C.Poisonous phosgene gas
D.Poisonous chlorine gas
单项选择题 A victim is coughing and wheezing from a partialobstruction of the airway. An observer should （）.
单项选择题 A victim has suffered a second-degree burn to a small area of the lower arm. What is the proper treatment for this injury?（）
单项选择题 A shipmate suffers a heart attack and stops breathing. You must（）.