平纹织物（ 最简单的织物）的开口循环每织入两纬，或每两个织造循环重复一次。

The shedding cycle for plain weave(which is the simplest weave) will repeat on two picks or two weaving cycles.

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这是一个恶性循环。每次感染都会使得原本细小的鼻窦开口更狭窄。

It's a vicious cycle: Each infection further Narrows the already small drainage openings.

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风扇盒(72)内的风扇(85)通过经挡板的顶部和底部开口(90)排出和经挡板(74)的中间开口吸入使经加热的空气循环。

A fan (85) in the fan box (72) circulates heated air by discharging via openings (90) in a top and a bottom and taking in via an intermediate opening of a baffle plate (74).

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