Oral nasal cup reduces fogging and lessens dead air space, limiting re-breathing of exhaled air.

口腔和鼻腔喷雾杯减少减轻死领空，限制重新呼吸呼出的空气。

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Oral nasal cup reduces fogging and lessens dead air space, limiting re-breathing of exhaled air.

口腔和鼻腔喷雾杯减少减轻死领空，限制重新呼吸呼出的空气。

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