invariant geological age

例句：

1. 1. The temperature invariant is the temperature at which the substance remains unchanged.
   温度不变是指物质在某一温度下保持不变。
2. 2.The invariant equation describes a relationship between two variables that remain constant regardless of changes in one variable.
   恒等方程描述了两个变量之间的关系，无论其中一个变量如何变化，这两个变量都保持不变。
3. 3. The invariant mass of an object is its mass when it is at rest or moving with constantvelocity.
   物体的惯性质量是它在静止或以恒定速度运动时的质量。