选择合适的选项补全短文。
It's 9 a.m.,the morning rush hour in Toronto.A man has fallen down on a downtown street suddenly.Several passers-by stop to help the man.One woman reaches into her purse for her cellphone and hits 911,the emergency number.____
Within ten minutes,the stricken man is in the back of an ambulance and is sent to the hospital for life-saving treatment.
This scene is fairly common in Toronto and other major cities.Over the years,cities have developed systems to respond quickly to emergencies____But none of this would be possible without the cooperation of car drivers who yield（让路）to emergency vehicles on busy downtown streets.In fact,it's against the law for drivers not to yield.
To yield means to give away or,more specifically,to get out of the way____As yet,China doesn't have any specific laws that require drivers to yield,whether it is for slower cars to move over to the inside lane of a highway or for all cars to give way to emergency vehicles____Drivers did not yield when they heard the ambulance's siren.
In Canada,failing to yield to an ambulance vehicle can result in a fine of $400~$2,000 and reduction of three points off your license.That's for a first offense.
____This punishment is severe because lives are in danger.
A.It has resulted in many lives being saved.
B.A second offense results in a bigger fine,the loss of your driver's license for two years and a possible jail sentence.
C.It saves lives and,who knows,someday it may save your own.
D.Three minutes later,sirens（警报）are heard in the distance as a police car,an ambulance and a fire truck race to the area.
E.It means pulling to the side of the road to let others pass.
F.Recently,an injured Beijing cyclist died on the way to hospital because the ambulance carrying him got stuck in city traffic.
G.Safe driving depends on driver's being aware of the traffic around them and yielding when necessary.
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