填空题
A--Do not block ventilation holes.
B--The amplifier should not be exposed to direct sunlight.
C--The amplifier should not be placed areas with high humidity or dust levels.
D---The amplifier should not be placed areas susceptible to vibration.
E--Make sure the power outlet conforms to the plug of the unit.
F--Do not use this unit if the electrical power cord is frayed or broken.
G--If an alarm rings while power has been turned on and signal has been fed, please turn it off and correct the trouble.