Each unit is supported by audio material in range of accents, available on audio CD or cassette.
每个单位的支持,音频素材,在一系列的口音,可在音频CD或录音带。
2
Commission experts estimate unit sales between 184 and 246 million for all portable audio devices just over the last four years, of which MP3 players range between 124 and 165 million.