parallel axis theorem

例句：

1. 1. This theory has been proven to be correct in many cases.
   这个理论在许多情况下已被证明是正确的。
2. 2. The parallel axis theorem is a fundamental principle of physics.
   平行轴定理是物理学的一个基本原理。
3. 3. In the study of crystal structure, the parallel axis theorem is crucial.
   在晶体结构研究中，平行轴定理至关重要。