But the fossil creatures had spiny limbs sprouting from their heads and circular, plated mouths, which opened and closed like the diaphragm of a camera.
这种生物头上伸出带刺的肢体，扁圆形的嘴巴就像照相机的光圈一样开开合合。
Options include direct acting and diaphragm type operations in a Normally Open or Normally Closed version.
可选包括直接作用和隔膜式常开或常闭版本。
Sanitary pump is single stage, single suction, full closed stainless steel centrifugal pump or pneumatic diaphragm valve.
进口卫生泵的型为单级、单吸、全封闭不锈钢离心泵或者气动隔膜阀。
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