And there is a large circular gap at the centre of the blades, which is safer for Marine life.

在叶片中心有一个大的圆形空间，可以让水中生物安全通过。

youdao

And there is a large circular gap at the centre of the blades, which is safer for Marine life.

在叶片中心有一个大的圆形空间，可以让水中生物安全通过。

youdao