They should not be relied upon to provide an error free method of relaying tone signalling to other decoders, such as a telephone exchange DTMF detector, for example.是什么意思_They should not be relied upon to provide an error free method of relaying tone signalling to other decoders, such as a telephone exchange DTMF detector, for example.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句