hub eddy

例句：

1. 1.The boat was caught in the strong current of the river.
   船被湍急的河流水流困住了。
2. 2. The car's engine is making a loud humming noise.
   汽车发动机发出嗡嗡声。
3. 3. The eddy around the tree creates a cool breeze.
   树周围的涡流产生了一阵凉爽的风。