除了某特别情况之外，所有动作应以一个向后的反作用力作开始。

All movements must begin with a backward motion with a very few exceptions.

youdao

因为根据牛顿定律，每个动作都有反作用力。

Because according to Newton, for every action there's an opposite reaction.

youdao

因为根据牛顿定律，每个动作都有反作用力。

Because according to Newton, for every action there's an opposite reaction.

youdao