英语翻译
Checking the remote control
These days almost every player comes with a wireless remote control.Some use ultrasonics ,but most operate using infrared signals.(Both are invisible and perfectly safe.)Become familiar with the controls,how they operate,and what they do.For this refer to the owner is manual.The signal from a remote control can be blocked if something is between the remote control and the player .Excessive distance between the two might also prevent operation.