constant declarator subscript

例句：

1. 1. The temperature is constantthroughout the day.
   温度在整个白天都是恒定的。
2. 2. The sun's rays are constantin their intensity and duration.
   太阳的光线强度和持续时间是恒定的。
3. 3. The riverflows steadily, its constant current providinga reliable source of water.
   河流平稳流动，其恒定的水流提供了可靠的水源。