From the wave viewpoint, a ray is an imaginary line drawn in the direction in which the wave is traveling.

 
  • 從波動(dòng)觀(guān)點(diǎn)來(lái)看,一條光線(xiàn)是一條假想的、按波行進(jìn)方向畫(huà)出的線(xiàn)。
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