tachist

例句：

1. 1. The tachist is a device used to measure the speed of objects.
   塔奇斯特是一种用于测量物体速度的设备。
2. 2. The tachist was invented by a scientist who wanted to study the movement of molecules.
   塔奇斯特是由一位科学家发明的，他想研究分子的运动。
3. 3. The tachist has been used in many scientific experiments to observe the behavior of materials under different conditions.
   塔奇斯特在许多科学实验中被用来观察不同条件下材料的行为。