the free wobble的用法和樣例：
例句
- Impulsion may be recognized by the freely swinging back and the participation of all the joints in the forward motion.
自由擺動的背部和身體所有關節都參與向前的運動是動力的表現。 - Until then, physicists had postulated boundary conditions in which no force acted on the ends of the strings, leaving them free to flap around.
當時，物理學家早已假定了沒有力作用在弦兩端的邊界條件，讓弦的末端可以自由擺動。
