Changing of beachfront can demonstrate that "the sea never stop" because of the tremendous power at sea is both created and destroyed at the same time.
The change of the beach can be demonstrated that that. "The sea has never stopped" because the sea with enormous energy. It is both a creator and a destroyer at the same time.
The changes of the beach can demonstrate that "the sea never stops." because the sea at the enormous energy. To both those who created and destroyed at the same time.