First aid (急救) is the care given to the injured or sick person as soon as possible after an accident or illness. It is this immediate care and attention before the arrival of the ambulance (救护车) that sometimes means the difference between life and death, or a full or partial recovery.
First aid has limitations, as not everybody is a doctor or expert, but it is a key element of the total medical system.
The principle to be adopted in first aid is immediate action. By-standers (旁观者) or relatives not knowing what to do, or being too fearful to try, have unwisely contributed or unnecessary deaths and worth injuries.
It is important that any action taken by the first aid provider is started as quickly as possible. Quick action is necessary to save life and parts of the body. One who is not breathing effectively, or is bleeding (流血) heavily, requires immediate help. If quick effective first aid is provided, then they have a much better chance of a good recovery.
But it should be remembered that any action taken is to be most careful, and fright (恐慌) by the first aid provider and by standers will not be good to the whole thing. Try to remain calm and think your action through. A calm and controlled first aider will give everyone confidence that the is being handled efficiently and effectively.The writer seems to suggest that if you don't know much about first aid, you should （）

A．call for help from professionals
B．still try to help
C．stand by and not try to help
D．learn it from a doctor