1. At breast height, measure the trunk diameter by a ruler. 在胸部高度的位置，用一把直尺量度干径。
2. Big cutter diameter, high cutting speed, good process quality. 刀具直径大，切割速度高，加工面质量好。
3. Measure (the rotor) to see whether its diameter is within tolerance or not. 测量（转子），看它的直径是否在公差允许范围之内。
英英解释
n.
1. the length of a straight line passing through the center of a circle and connecting two points on th
2. a straight line connecting the center of a circle with two points on its perimeter (or the center of
