flicker fusion frequency

例句：

1. 1. The flicker of the candles in the room was barely visible.
   房间里蜡烛的闪烁几乎看不见。
2. 2. The fusion frequency of the two frequencies is determined by their relative phase angle.
   两个频率的融合频率由它们之间的相对相位角决定。
3. 3. The flickering lights in the park were a stark contrast to the darkness.
   公园里摇曳的灯光与黑暗形成了鲜明的对比。