并提出了以软件形式判断发射端光链路状态，从而实现双纤自愈功能。
Moreover, the design judges link-state , then achieves system self-healing function.
DS01收发器光模块可用双纤光模块，也可选用单纤光模块。选用单纤双向光模块时收发器必须成对使用。
DS01 single mode media converter may be used double optical fiber-module or single optical fiber-module which must be used in couples.
她是个羞怯纤美的姑娘，长着一双蓝色的大眼睛。
She was a shy, delicately pretty girl with enormous blue eyes.
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