oarweed

例句：

1. 1. The boat sank into the water, leaving only oarweed floating on the surface.
   船沉入水中，只有水草在水面上漂浮。
2. 2. The fisherman was fishing for oarweed when he heard the sound of a motorboat approaching.
   渔民正在捕鱼时，听到了摩托艇的声音。
3. 3.The oarweed in the lake is a common food source for some animals.
   湖中的水草是某些动物的常见食物来源。