The teeth can be used like a ruler to measure the light emitted by lasers, atoms, stars, or other objects with extraordinarily high precision.

这些齿可以像尺子一样用来异常精确的测量激光器、原子、天体或其它物体发出的光的频率。

youdao

Using a ruler, mark a light line with your pencil down the left-hand edge, about 1-2cm in.

用尺子在左边画一条直线，离边缘1 - 2厘米。

youdao

Methods To do quality control experiments to simulate the process of 3D-CRT by means of Topsland system, radiation treatment -planning system, laser light, bow form ruler, head model.

方法采用拓能系统的固定装置、计划系统、激光灯、弓形尺、头部模型（简称头模）模拟3D CRT的实施过程进行质量控制分组实验。

youdao