level line的用法和樣例：
例句
- The indifference curve may be compared with a contour line on a map.
無差別曲線可以與地圖上的等高線相比擬。 - Assuming a horizontal block of ups and downs on the ground, the water's surface and materials County line is a continuous contour.
假設用一個水平面街區高低起伏的地面，則水品縣與地面的交線就是一條連續不斷的等高線。 - The vertical line meets the horizontal one here.
垂直線與水平線在此相交。 - Fill the generator with fresh water above the normal water level.
給發生器注入正常水平線以上的清水。
