at grade
在同一平面的交道口
Grade n.
1. A step or degree in any series, rank, quality, order; relative position or standing; as, grades of military rank; crimes of every grade; grades of flour.
They also appointed and removed, at their own pleasure,
teachers of every grade. --Buckle.
2. In a railroad or highway: (a) The rate of ascent or descent; gradient; deviation from a level surface to an inclined plane; -- usually stated as so many feet per mile, or as one foot rise or fall in so many of horizontal distance; as, a heavy grade; a grade of twenty feet per mile, or of 1 in 264. (b) A graded ascending, descending, or level portion of a road; a gradient.
3. Stock Breeding The result of crossing a native stock with some better breed. If the crossbreed have more than three fourths of the better blood, it is called high grade.
At grade, on the same level; -- said of the crossing of a railroad with another railroad or a highway, when they are on the same level at the point of crossing.
Down grade, a descent, as on a graded railroad.
Up grade, an ascent, as on a graded railroad.
Equating for grades. See under Equate.
Grade crossing, a crossing at grade.