The following figure shows the element tree for datum planes. 下圖展示了基準平面的元素樹。
It shows that, apart from the usual elements for the tree root and feature type, a datum plane contains the positioning constraints and an optional fit type. 它展示了，除了通常的樹根和特徵類型等元素，一個基準平面包含位置約束和一個可選配合類型。
Well Log Datum Velocity Correction. 井曲線基準面校正。
All elevations are relative to chart datum. 所有標高均相對於海圖基準面。
Some parts of the country are below sea level. 那個國家的某些部分位於海平面之下。
I wanted to watch the sun rising above the sea level. 我想看見太陽在海平面上升起。
