开启排气针形阀，并从软管排放空气。然后关闭排气阀。

Open vent needle valve and bleed air from hose. Then close vent valve.

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开启阀门A从排气软管处排出空气。

Open valve a to vent air from the vent hose.

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开启阀门A从排气软管处排出空气。

Open valve a to vent air from the vent hose.

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