In 1568, the Untied States government wanted one number that people could call for emergencies. They decided that 911 was easy to remember and people could dial it quickly. The very first 911 call was made on February 16, 1968. in Alibama. Today, 911 is used for emergencies in most parts of the United States and many parts of Canada.
Other countries may use other numbers. In Great Britain, it's 959. If you're not sure which emergency number is used in your area, check your phone book.
When to call
Never call 911 as a joke or just to see what might happen. The only time you should call 911
When in an emergency call
When you dial the 911 operator(接线员)，it's always OK to give out your information. Speak slowly and clearly when you explain what's happening. What happened? Where are you? Who needs help?
Don't hang up(挂断)！
If you have to call 911, do not hang up until the operator tells you it's OK to do so, That way, you can be sure that the operator has all the information to offer help fast.
A dog named Faith dialed 911 when her owner who was in a wheelchair fell and needed help. She had been taught to use a speed—dial(快递拨号)function.
