单项选择题
A.On their side if unconscious
B.Head down and feet up，no injuries to face or head
C.Flat on their back with head and feet at the same level
D.Arms above their head
单项选择题 A man has suffered a burn on the arm. There is a reddening of the skin but no other apparent damage. Using standard MEDICAL terminology，this is a（）.
单项选择题 A man has a burn on his arm. There is reddening of the skin，blistering，and swelling. Using standard medical terminology this is a（）.
单项选择题 A major health hazard of the product tert-butylamine is that it（）.