降低下层桨的离底高度能加强下层桨的径向流动，并增大上层桨叶轮区和循环区流体的轴向流动。

With the decreasing of C1, the radial flow generated by the lower impeller, the axial flow generated by the upper impeller, and the axial flow of the main circulation increased.

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这是个普通的早餐食品，特别是在城市中，对于低下层的人名来讲，新鲜的鱼是十分稀有和昂贵的。

It was once a common breakfast food, especially for the lower classes in the cities where fresh fish would be rare and expensive.

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