darkening rate的用法和样例：
例句
- The increased darkening of the sky toward the right indicates the darkened atmosphere created by the passing shadow cone of the total solar eclipse.
右侧的天空逐渐变暗这就表明日全食的影锥通过了地球的大气层，使得那里变暗。 - It may serve, let us hope, to symbolize some sweet moral blossom, that may be found along the track, or relieve the darkening close of a tale of human frailty and sorrow.
它可作为，让我们希望，象征甜蜜的一些道德开花，这可能是沿著轨道发现，或减轻人类的脆弱和悲伤的故事变暗关闭。
