built-in end的用法和樣例：
例句
- Each microactuator consists of two PT arms that are jointed at the free end and connected to an anchor at the fixed end.
該微驅動器由兩個光熱膨脹臂構成，兩者在自由端相互連接，而在固定端分別通過細橋與基底相連。 - Another theory is that having a greater mass under the fixed end of the reed somehow improves the vibratory properties of the reed itself.
還有一個理論認為簧片固定端下面較大的質量會提升簧片的振動特性。
