constant cyclic code

例句：

1. 1. The temperature isconstant throughout the day.
   温度在整个一天中保持不变。
2. 2. The sun's rays are constantin their warmth.
   太阳的光线始终温暖如初。
3. 3. The river flows with aconstant current.
   河流以恒定的流速流动。