英语翻译

英语翻译
**** When a CD is played,the laser beam shines on the disk from below and passes through a protective thin transparent layer on the disk to focus on an aluminum reflecting film or signal surface.At the surface where the pits are recorded,the diameter of the laser beam is a mere 1.7 micrometers,Even if the protective transparent layer on the CD becomes dusty or scratched,the laser beam is so finely focused that most of these do not affect playing quality because they are out of focus.
1 the laser beam is so finely focused that most of these do not affect playing quality because they are out of focus.
**** And the laser it self lasts 10 times longer than a diamond phonograph stylus.
2 激光本身也要比留声机的钻石唱针使用寿命久十倍?
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