tidal indicator

例句：

1. 1. The tide is rising, and the beach is getting crowded.
   潮水正在上涨，海滩上的人越来越多。
2. 2. The tidal indicator showed that the storm was coming.
   潮汐指示器显示暴风雨即将来临。
3. 3. The scientists used the tidal indicator to study the ocean currents.
   科学家们使用潮汐指示器研究海洋洋流。