91色情片

Sad but true: a new gun alarm is supposed to let Americans keep loaded guns
but stop their children playing with the weapons. The students at Yale
University who invented the device hope it will reduce the annual toll of 1300
deaths in shooting accidents. The Gun Guard uses a mercury switch, which acts as
a motion sensor, connected to a 120 decibel alarm. If the gun moves a
millimetre, a shrill alarm sounds.