Water

Water is important element in this life. Because without water we can't life. All creatures need water. Plant need water, animal need water, and of course human also need water. In the earth water covered almost 2/3 the planet and commonly found in the ocean. Water have cycle or called water cycle. Water cycle happen when the sun absorb the water from the land and acoomodated in the cloud, after the cloud can't hold anymore so the rain is fall and like that repeatedly.

Wave

Wave is a chant who can spread with air, water, or any possible media.
Wave on air can be a ultrasonic sound, hypersonic sound, or echoes.
Wave on air can be like a ocean wave, but the big ocen wave can be disaster fo human life, because can make a tsunami. On the land wave can be like a earthquake.