A laser beam like the one pictured up top combines short and long pulses of light to identify individual molecules with a high degree of precision from a safe distance.
一道激光射线由或短或长的光脉冲组合而成，从而能在一个安全的距离高精度地辨别单个的分子。
2
If your foot points down, you need to measure the distance between the top of your big toe and an imaginary line from the bottom of your heel.
如果你的脚底朝下，那么你需要测量你的脚后跟到你大脚趾所在垂线的最短距离。
3
When you select an HTML element, Expression Web also shows a small bubble with additional information, such as size, distancefrom the left, and distancefrom the top.