mechanism with single degree of freedom

例句：

1. 1.The mechanism of the machine is very simple.
   这台机器的机制非常简单。
2. 2. The new design has a more efficient mechanism.
   新设计有一个更高效的机制。
3. 3. The scientist used a microscope to observe the internal structure of the mechanism.
   科学家使用显微镜观察了机器的内部结构。