Anechoic coating is crucial to the submarine stealth technology and is a major part of quiet-submarine design.

声学覆盖层是水下航行体隐身的一项关键技术，在安静型水下航行体设计中占有十分重要的地位。

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Consider the case nearly two decades ago of the Soviet Union's illegal acquisition of tools needed to produce very quiet submarine propellers.

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The best known of such incidents was that involving the sale by Toshiba and Kongsberg of advanced machine tools and enabling software to the USSR for the purpose of producing extremely quiet submarine propellers.

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For instance, a submarine must be quiet and a smart bomb must be accurate.

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