tidal

他的情绪像潮汐一样起伏不定。

His mood has a ___tidal rise and fall.

这个海滩上的活动都根据潮汐时间表安排。

Activities on this beach are scheduled according to the ___tidal timetable.

我们计划在涨潮时去海滩捡贝壳。

We planned to go to the beach for shell collecting during the ___tidal rise.