free-pendulum clock

例句：

1. 1.The free-pendulum clock inthe museum is fascinating to watch.
   博物馆里的自由摆钟令人着迷。
2. 2. The free-pendulum clock was designed bya famous clockmaker.
   这个自由摆钟是由一位著名的钟表匠设计的。
3. 3. The free-pendulum clock has been usedfor centuries as a scientific instrument.
   自由摆钟作为一种科学仪器，已经使用了好几个世纪。