That which soaks into the ground is the most valuable because it remains on the earth longest and is the purest. 伯莎M.克拉克.科学通论.
When water falls upon a field, it soaks into the ground, or collects in puddles which slowly evaporate, or it runs off and drains into small streams or into rivers. 伯莎M.克拉克.科学通论.