Because the soft film smallpox is a soft material, is to determine its shape according to the shape of the keel.

软膜天花是一种软性材料，是根据龙骨的形状来确定它的形状。

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The keel arranged on the board is in a radiation shape from the tube head to the outside;

设置在上述板面上的龙骨呈从管头向外边的放射状。

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